diff --git a/ethereumj-core/src/main/java/org/ethereum/config/SystemProperties.java b/ethereumj-core/src/main/java/org/ethereum/config/SystemProperties.java
index 3c5b5520..860fb9bd 100644
--- a/ethereumj-core/src/main/java/org/ethereum/config/SystemProperties.java
+++ b/ethereumj-core/src/main/java/org/ethereum/config/SystemProperties.java
@@ -40,7 +40,6 @@ public class SystemProperties {
         
     	try {
             String userDir = System.getProperty("user.dir");
-            System.out.println(userDir);
             String fileName = userDir + "/config/system.properties";
             File file = new File(fileName);
 
diff --git a/ethereumj-core/src/main/java/org/ethereum/core/Block.java b/ethereumj-core/src/main/java/org/ethereum/core/Block.java
index 90db08c0..ed09578d 100644
--- a/ethereumj-core/src/main/java/org/ethereum/core/Block.java
+++ b/ethereumj-core/src/main/java/org/ethereum/core/Block.java
@@ -71,7 +71,7 @@ public class Block {
 				timestamp, extraData, nonce);
         this.txsState = new Trie(null);
 
-        byte[] stateRoot = WorldManager.instance.repository.getRootHash();
+        byte[] stateRoot = WorldManager.getInstance().getRepository().getRootHash();
         this.header.setStateRoot(stateRoot);
 
         this.header.setTxTrieRoot(txsState.getRootHash());
@@ -108,9 +108,7 @@ public class Block {
     }
 
     public Block getParent() {
-		byte[] rlpEncoded = WorldManager.instance.chainDB.get(ByteUtil
-				.longToBytes(this.getNumber() - 1));
-    	return new Block(rlpEncoded);
+		return WorldManager.getInstance().getBlockChain().getByNumber(this.getNumber() - 1);
     }
     
     public byte[] getParentHash() {
diff --git a/ethereumj-core/src/main/java/org/ethereum/core/Blockchain.java b/ethereumj-core/src/main/java/org/ethereum/core/Blockchain.java
index 278df3ab..ebdebc18 100644
--- a/ethereumj-core/src/main/java/org/ethereum/core/Blockchain.java
+++ b/ethereumj-core/src/main/java/org/ethereum/core/Blockchain.java
@@ -54,7 +54,7 @@ public class Blockchain {
 	// to avoid using minGasPrice=0 from Genesis for the wallet
 	private static long INITIAL_MIN_GAS_PRICE = 10 * SZABO.longValue();
 		
-	private DatabaseImpl db;
+	private DatabaseImpl chainDb;
 	private Wallet wallet;
 	
     private long gasPrice = 1000;
@@ -69,9 +69,8 @@ public class Blockchain {
     private Map<String, WalletTransaction> walletTransactions =
             Collections.synchronizedMap(new HashMap<String, WalletTransaction>());
 
-	public Blockchain(Wallet wallet) {
-		this.db = WorldManager.instance.chainDB;
-		this.wallet = wallet;
+	public Blockchain() {
+		this.chainDb = new DatabaseImpl("blockchain");
 	}
 
 	public Block getLastBlock() {
@@ -86,8 +85,8 @@ public class Blockchain {
         return index.size();
     }
 
-    public Block getByNumber(long rowIndex) {
-        return new Block(db.get(ByteUtil.longToBytes(rowIndex)));
+    public Block getByNumber(long blockNr) {
+        return new Block(chainDb.get(ByteUtil.longToBytes(blockNr)));
     }
 
     public void addBlocks(List<Block> blocks) {
@@ -119,7 +118,7 @@ public class Blockchain {
 //            String blockState = Hex.toHexString(block.getStateRoot());
 //            logger.debug("New world stateRoot {} and block stateRoot {}", newState, blockState);
             
-            db.put(ByteUtil.longToBytes(block.getNumber()), block.getEncoded());
+            this.chainDb.put(ByteUtil.longToBytes(block.getNumber()), block.getEncoded());
             if (logger.isDebugEnabled())
                 logger.debug("block added to the chain with hash: {}", Hex.toHexString(block.getHash()));
         }
@@ -128,23 +127,23 @@ public class Blockchain {
             for (Transaction tx : block.getTransactionsList()) {
                 if (logger.isDebugEnabled())
                     logger.debug("pending cleanup: tx.hash: [{}]", Hex.toHexString( tx.getHash()));
-                removeWalletTransaction(tx);
+                this.removeWalletTransaction(tx);
             }
         }
         logger.info("*** Block chain size: [ {} ]", index.size());
     }
     
-    private void addBlock(Block block) {
+    public void addBlock(Block block) {
     	if(block.isValid()) {
 
             if (!block.isGenesis())
-                WorldManager.instance.applyBlock(block);
+                WorldManager.getInstance().applyBlock(block);
 
 			this.wallet.processBlock(block);
 	        // In case of the genesis block we don't want to rely on the min gas price 
 			this.gasPrice = block.isGenesis() ? INITIAL_MIN_GAS_PRICE : block.getMinGasPrice();
-			setLastBlock(block);
-			index.put(block.getNumber(), block.getParentHash());
+			this.setLastBlock(block);
+			this.index.put(block.getNumber(), block.getParentHash());
     	} else {
     		logger.warn("Invalid block with nr: {}", block.getNumber());
     	}
@@ -180,6 +179,10 @@ public class Blockchain {
         logger.info("pending transaction removed with hash: {} ",  hash);
         walletTransactions.remove(hash);
     }
+    
+    public void setWallet(Wallet wallet)  {
+    	this.wallet = wallet;
+    }
 
     public byte[] getLatestBlockHash() {
             if (index.isEmpty())
@@ -188,21 +191,21 @@ public class Blockchain {
                 return getLastBlock().getHash();
     }
     
-	public void loadChain() {
-		DBIterator iterator = db.iterator();
+	public void load() {
+		DBIterator iterator = chainDb.iterator();
 		try {
 			if (!iterator.hasNext()) {
                 logger.info("DB is empty - adding Genesis");
                 this.lastBlock = Genesis.getInstance();
                 this.addBlock(lastBlock);
                 logger.debug("Block #{} -> {}", Genesis.NUMBER, lastBlock.toFlatString());
-                db.put(ByteUtil.longToBytes(Genesis.NUMBER), lastBlock.getEncoded());
+                chainDb.put(ByteUtil.longToBytes(Genesis.NUMBER), lastBlock.getEncoded());
             }
 
             logger.debug("Displaying blocks stored in DB sorted on blocknumber");
             long blockNr = Genesis.NUMBER;
             for (iterator.seekToFirst(); iterator.hasNext(); iterator.next()) {
-                this.lastBlock = new Block(db.get(ByteUtil.longToBytes(blockNr)));
+                this.lastBlock = new Block(chainDb.get(ByteUtil.longToBytes(blockNr)));
                 logger.debug("Block #{} -> {}", lastBlock.getNumber(), lastBlock.toFlatString());
                 this.addBlock(lastBlock);
                 blockNr = lastBlock.getNumber()+1;
@@ -216,4 +219,9 @@ public class Blockchain {
 			}
 		}
 	}
+	
+    public void close() {
+        if (this.chainDb != null)
+            chainDb.close();
+    }
 }
diff --git a/ethereumj-core/src/main/java/org/ethereum/core/Genesis.java b/ethereumj-core/src/main/java/org/ethereum/core/Genesis.java
index fdb0d96f..2a4d1ccb 100644
--- a/ethereumj-core/src/main/java/org/ethereum/core/Genesis.java
+++ b/ethereumj-core/src/main/java/org/ethereum/core/Genesis.java
@@ -67,15 +67,14 @@ public class Genesis extends Block {
         // The proof-of-concept series include a development premine, making the state root hash
         // some value stateRoot. The latest documentation should be consulted for the value of the state root.
 		for (String address : premine) {
-            WorldManager.instance.repository.createAccount(Hex.decode(address));
-            WorldManager.instance.repository.addBalance   (Hex.decode(address), BigInteger.valueOf(2).pow(200) );
+            WorldManager.getInstance().getRepository().createAccount(Hex.decode(address));
+            WorldManager.getInstance().getRepository().addBalance   (Hex.decode(address), BigInteger.valueOf(2).pow(200) );
         }
-
-        this.setStateRoot( WorldManager.instance.repository.getRootHash() );
+		this.setStateRoot(WorldManager.getInstance().getRepository().getRootHash());
+        WorldManager.getInstance().getRepository().dumpState(0, 0, null);
+        
 		logger.info("Genesis-hash: " + Hex.toHexString(this.getHash()));
 		logger.info("Genesis-stateRoot: " + Hex.toHexString(this.getStateRoot()));
-
-        WorldManager.instance.repository.dumpState(0, 0, null);
     }
 	
 	public static Block getInstance() {
diff --git a/ethereumj-core/src/main/java/org/ethereum/db/DatabaseImpl.java b/ethereumj-core/src/main/java/org/ethereum/db/DatabaseImpl.java
index 75913654..a8df7182 100644
--- a/ethereumj-core/src/main/java/org/ethereum/db/DatabaseImpl.java
+++ b/ethereumj-core/src/main/java/org/ethereum/db/DatabaseImpl.java
@@ -37,7 +37,6 @@ public class DatabaseImpl implements Database {
 		try {
 			logger.debug("Opening database");
 			if(SystemProperties.CONFIG.databaseReset()) {
-				logger.debug("Destroying '" + name + "' DB on startup ENABLED");
 				destroyDB(name);
 			}
 			logger.debug("Initializing new or existing DB: '" + name + "'");
@@ -62,16 +61,16 @@ public class DatabaseImpl implements Database {
 		}
 	}
 	
-	/** Insert object(value) (key = sha3(value)) */
-	public void put(byte[] key, byte[] value) {
-		db.put(key, value);
-	}
-	
 	/** Get object (key) -> value */
 	public byte[] get(byte[] key) {
 		return db.get(key);
 	}
 	
+	/** Insert object(value) (key = sha3(value)) */
+	public void put(byte[] key, byte[] value) {
+		db.put(key, value);
+	}
+	
 	/** Delete object (key) from db **/
 	public void delete(byte[] key) {
 		delete(key);
diff --git a/ethereumj-core/src/main/java/org/ethereum/db/TrackDatabase.java b/ethereumj-core/src/main/java/org/ethereum/db/TrackDatabase.java
index d1e7c2b2..87ae8f1d 100644
--- a/ethereumj-core/src/main/java/org/ethereum/db/TrackDatabase.java
+++ b/ethereumj-core/src/main/java/org/ethereum/db/TrackDatabase.java
@@ -44,7 +44,7 @@ public class TrackDatabase implements Database {
 
     public void put(byte[] key, byte[] value) {
         if (trackingChanges) {
-            changes.put(  new ByteArrayWrapper(key)  , value);
+			changes.put(new ByteArrayWrapper(key), value);
         } else {
             db.put(key, value);
         }
diff --git a/ethereumj-core/src/main/java/org/ethereum/gui/BlockChainTable.java b/ethereumj-core/src/main/java/org/ethereum/gui/BlockChainTable.java
index 1bc9b320..0a1d0fbf 100644
--- a/ethereumj-core/src/main/java/org/ethereum/gui/BlockChainTable.java
+++ b/ethereumj-core/src/main/java/org/ethereum/gui/BlockChainTable.java
@@ -31,7 +31,7 @@ public class BlockChainTable extends JFrame {
         this.toolBar = toolBar;
         addCloseAction();
 
-        final BlockChainTable blockChainTable = this;
+        final BlockChainTable blockchainTable = this;
 
         setTitle("Block Chain Table");
         setSize(700, 400);
@@ -48,7 +48,7 @@ public class BlockChainTable extends JFrame {
         topPanel.setLayout(new BorderLayout());
         getContentPane().add(topPanel);
 
-        // Create a new table instance
+        // Create a new table getInstance()
         table = new JTable();
         table.setModel(new BlockTableModel());
 
@@ -74,9 +74,9 @@ public class BlockChainTable extends JFrame {
             @Override
             public void actionPerformed(ActionEvent e) {
 
-                if (WorldManager.instance.getBlockChain().getSize() - 1 < lastFindIndex) return;
+                if (WorldManager.getInstance().getBlockChain().getSize() - 1 < lastFindIndex) return;
 
-                Block block = WorldManager.instance.getBlockChain().getByNumber(lastFindIndex);
+                Block block = WorldManager.getInstance().getBlockChain().getByNumber(lastFindIndex);
                 StringSelection stsel = new StringSelection(block.toString());
                 Clipboard system = Toolkit.getDefaultToolkit().getSystemClipboard();
                 system.setContents(stsel,stsel);
@@ -88,7 +88,7 @@ public class BlockChainTable extends JFrame {
             @Override
             public void actionPerformed(ActionEvent e) {
 
-                String toFind = JOptionPane.showInputDialog(blockChainTable, "Find:",
+                String toFind = JOptionPane.showInputDialog(blockchainTable, "Find:",
                         "Find in BlockChain", JOptionPane.QUESTION_MESSAGE);
 
                 if (toFind.equals("")) {
@@ -96,10 +96,10 @@ public class BlockChainTable extends JFrame {
                     return;
                 }
 
-                for (int i = lastFindIndex + 1; i < WorldManager.instance.getBlockChain().getSize(); ++i) {
+                for (int i = lastFindIndex + 1; i < WorldManager.getInstance().getBlockChain().getSize(); ++i) {
 
-                    if (WorldManager.instance.getBlockChain().getSize() - 1 < i) return;
-                    Block block = WorldManager.instance.getBlockChain().getByNumber(i);
+                    if (WorldManager.getInstance().getBlockChain().getSize() - 1 < i) return;
+                    Block block = WorldManager.getInstance().getBlockChain().getByNumber(i);
                     boolean found = block.toString().toLowerCase().contains(toFind.toLowerCase());
                     if (found) {
                         // TODO: now we find the first occur
diff --git a/ethereumj-core/src/main/java/org/ethereum/gui/BlockTableModel.java b/ethereumj-core/src/main/java/org/ethereum/gui/BlockTableModel.java
index e86b9b87..d74685d8 100644
--- a/ethereumj-core/src/main/java/org/ethereum/gui/BlockTableModel.java
+++ b/ethereumj-core/src/main/java/org/ethereum/gui/BlockTableModel.java
@@ -16,7 +16,7 @@ public class BlockTableModel extends AbstractTableModel {
     public int getRowCount() {
 
         fireTableDataChanged();
-        int rowCount = WorldManager.instance.getBlockChain().getSize();
+        int rowCount = WorldManager.getInstance().getBlockChain().getSize();
         return rowCount;
     }
 
@@ -31,7 +31,7 @@ public class BlockTableModel extends AbstractTableModel {
 //        byte[] hash = MainData.instance.getAllBlocks().get(rowIndex).getHash();
 //        return Hex.toHexString(hash);
 
-        Block block = WorldManager.instance.getBlockChain().getByNumber(rowIndex);
+        Block block = WorldManager.getInstance().getBlockChain().getByNumber(rowIndex);
         if (block == null) return "";
 
         return block.toString();
diff --git a/ethereumj-core/src/main/java/org/ethereum/gui/ContractCallDialog.java b/ethereumj-core/src/main/java/org/ethereum/gui/ContractCallDialog.java
index 2358fa8c..8b2b3218 100644
--- a/ethereumj-core/src/main/java/org/ethereum/gui/ContractCallDialog.java
+++ b/ethereumj-core/src/main/java/org/ethereum/gui/ContractCallDialog.java
@@ -174,7 +174,7 @@ class ContractCallDialog extends JDialog implements MessageAwareDialog {
         editor.setForeground(Color.RED);
 
         Collection<Account> accounts =
-                WorldManager.instance.getWallet().getAccountCollection();
+                WorldManager.getInstance().getWallet().getAccountCollection();
 
         for (Account account : accounts) {
             creatorAddressCombo.addItem(new AccountWrapper(account));
@@ -226,8 +226,8 @@ class ContractCallDialog extends JDialog implements MessageAwareDialog {
         }
 
         byte[] contractAddress = Hex.decode( contractAddr );
-        final byte[] programCode = WorldManager.instance.repository.getCode(contractAddress);
-        final Map storageMap = WorldManager.instance.repository.getContractDetails(contractAddress).getStorage();
+        final byte[] programCode = WorldManager.getInstance().getRepository().getCode(contractAddress);
+        final Map storageMap = WorldManager.getInstance().getRepository().getContractDetails(contractAddress).getStorage();
 
         contractDataInput.setBounds(70, 80, 350, 145);
         contractDataInput.setViewportView(msgDataTA);
@@ -301,13 +301,13 @@ class ContractCallDialog extends JDialog implements MessageAwareDialog {
     private void playContractCall() {
 
         byte[] contractAddress = Hex.decode(contractAddrInput.getText());
-        ContractDetails contractDetails =  WorldManager.instance.repository.getContractDetails(contractAddress);
+        ContractDetails contractDetails =  WorldManager.getInstance().getRepository().getContractDetails(contractAddress);
         if (contractDetails == null) {
             alertStatusMsg("No contract for that address");
             return;
         }
 
-        byte[] programCode = WorldManager.instance.repository.getCode(contractAddress);
+        byte[] programCode = WorldManager.getInstance().getRepository().getCode(contractAddress);
         if (programCode == null || programCode.length == 0) {
             alertStatusMsg("Such account exist but no code in the db");
             return;
@@ -316,7 +316,7 @@ class ContractCallDialog extends JDialog implements MessageAwareDialog {
         Transaction tx = createTransaction();
         if (tx == null) return;
 
-        ProgramPlayDialog.createAndShowGUI(programCode, tx, WorldManager.instance.getBlockChain().getLastBlock());
+        ProgramPlayDialog.createAndShowGUI(programCode, tx, WorldManager.getInstance().getBlockChain().getLastBlock());
     }
 
     protected JRootPane createRootPane() {
@@ -460,15 +460,15 @@ class ContractCallDialog extends JDialog implements MessageAwareDialog {
     }
 
     public static void main(String args[]) {
-        WorldManager.instance.getWallet();
-        WorldManager.instance.loadChain();
+        WorldManager.getInstance().getWallet();
+        WorldManager.getInstance().loadBlockChain();
         ContractCallDialog ccd = new ContractCallDialog(null);
         ccd.setVisible(true);
         ccd.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
         ccd.addWindowListener(new WindowAdapter() {
             @Override
             public void windowClosed(WindowEvent e) {
-                WorldManager.instance.close();
+                WorldManager.getInstance().close();
             }
         });
     }
diff --git a/ethereumj-core/src/main/java/org/ethereum/gui/ContractSubmitDialog.java b/ethereumj-core/src/main/java/org/ethereum/gui/ContractSubmitDialog.java
index 60c3d974..4915f7bd 100644
--- a/ethereumj-core/src/main/java/org/ethereum/gui/ContractSubmitDialog.java
+++ b/ethereumj-core/src/main/java/org/ethereum/gui/ContractSubmitDialog.java
@@ -108,7 +108,7 @@ class ContractSubmitDialog extends JDialog implements MessageAwareDialog {
                         contractAddrInput.setText(Hex.toHexString(tx.getContractAddress()));
 
                         ProgramPlayDialog.createAndShowGUI(tx.getData(), tx,
-                                WorldManager.instance.getBlockChain().getLastBlock());
+                                WorldManager.getInstance().getBlockChain().getLastBlock());
                     }}
         );
 
@@ -170,7 +170,7 @@ class ContractSubmitDialog extends JDialog implements MessageAwareDialog {
         editor.setForeground(Color.RED);
 
         Collection<Account> accounts =
-                WorldManager.instance.getWallet().getAccountCollection();
+                WorldManager.getInstance().getWallet().getAccountCollection();
 
         for (Account account : accounts) {
             creatorAddressCombo.addItem(new AccountWrapper(account));
@@ -302,7 +302,7 @@ class ContractSubmitDialog extends JDialog implements MessageAwareDialog {
 
         Account account = ((AccountWrapper)creatorAddressCombo.getSelectedItem()).getAccount();
         BigInteger currentBalance = account.getBalance();
-        BigInteger gasPrice = BigInteger.valueOf(WorldManager.instance.getBlockChain().getGasPrice());
+        BigInteger gasPrice = BigInteger.valueOf(WorldManager.getInstance().getBlockChain().getGasPrice());
         BigInteger gasInput = new BigInteger( this.gasInput.getText());
 
         boolean canAfford = currentBalance.compareTo(gasPrice.multiply(gasInput)) >= 0;
diff --git a/ethereumj-core/src/main/java/org/ethereum/gui/DialogWorker.java b/ethereumj-core/src/main/java/org/ethereum/gui/DialogWorker.java
index c95b346e..619899fd 100644
--- a/ethereumj-core/src/main/java/org/ethereum/gui/DialogWorker.java
+++ b/ethereumj-core/src/main/java/org/ethereum/gui/DialogWorker.java
@@ -58,7 +58,7 @@ public class DialogWorker extends SwingWorker<Transaction, Object> {
         }
 
         dialog.infoStatusMsg("Transaction got approved");
-        WorldManager.instance.getWallet().applyTransaction(tx);
+        WorldManager.getInstance().getWallet().applyTransaction(tx);
         return null;
     }
 }
diff --git a/ethereumj-core/src/main/java/org/ethereum/gui/PayOutDialog.java b/ethereumj-core/src/main/java/org/ethereum/gui/PayOutDialog.java
index ad4cf243..e0a1e040 100644
--- a/ethereumj-core/src/main/java/org/ethereum/gui/PayOutDialog.java
+++ b/ethereumj-core/src/main/java/org/ethereum/gui/PayOutDialog.java
@@ -119,7 +119,7 @@ class PayOutDialog extends JDialog implements MessageAwareDialog {
 				byte[] senderPrivKey = account.getEcKey().getPrivKeyBytes();
 				byte[] nonce = accountState.getNonce() == BigInteger.ZERO ? null : accountState.getNonce().toByteArray();
 
-                byte[] gasPrice = BigInteger.valueOf( WorldManager.instance.getBlockChain().getGasPrice()).toByteArray();
+                byte[] gasPrice = BigInteger.valueOf( WorldManager.getInstance().getBlockChain().getGasPrice()).toByteArray();
 
 				Transaction tx = new Transaction(nonce, gasPrice, BigIntegers
 						.asUnsignedByteArray(fee), address, BigIntegers
@@ -194,7 +194,7 @@ class PayOutDialog extends JDialog implements MessageAwareDialog {
         // check if the tx is affordable
         BigInteger ammountValue = new BigInteger(amountText);
         BigInteger feeValue = new BigInteger(feeText);
-        BigInteger gasPrice = BigInteger.valueOf(WorldManager.instance.getBlockChain().getGasPrice());
+        BigInteger gasPrice = BigInteger.valueOf(WorldManager.getInstance().getBlockChain().getGasPrice());
         BigInteger currentBalance = accountState.getBalance();
 
         boolean canAfford = gasPrice.multiply(feeValue).add(ammountValue).compareTo(currentBalance) != 1;
diff --git a/ethereumj-core/src/main/java/org/ethereum/gui/ProgramPlayDialog.java b/ethereumj-core/src/main/java/org/ethereum/gui/ProgramPlayDialog.java
index 104c506d..9b6aff30 100644
--- a/ethereumj-core/src/main/java/org/ethereum/gui/ProgramPlayDialog.java
+++ b/ethereumj-core/src/main/java/org/ethereum/gui/ProgramPlayDialog.java
@@ -4,7 +4,6 @@ import org.ethereum.core.Block;
 import org.ethereum.core.Transaction;
 import org.ethereum.db.Repository;
 import org.ethereum.manager.WorldManager;
-import org.ethereum.serpent.SerpentCompiler;
 import org.ethereum.vm.*;
 import org.spongycastle.util.encoders.Hex;
 
@@ -52,7 +51,7 @@ public class ProgramPlayDialog extends JPanel implements ActionListener,
         outputList = new ArrayList<String>();
         VM vm = new VM();
 
-        Repository tractRepository = WorldManager.instance.repository.getTrack();
+        Repository tractRepository = WorldManager.getInstance().getRepository().getTrack();
 
         Program program = new Program(code ,
                 ProgramInvokeFactory.createProgramInvoke(tx, lastBlock, tractRepository));
diff --git a/ethereumj-core/src/main/java/org/ethereum/gui/ToolBar.java b/ethereumj-core/src/main/java/org/ethereum/gui/ToolBar.java
index f369de04..ee3550f3 100644
--- a/ethereumj-core/src/main/java/org/ethereum/gui/ToolBar.java
+++ b/ethereumj-core/src/main/java/org/ethereum/gui/ToolBar.java
@@ -24,7 +24,7 @@ public class ToolBar extends JFrame {
 
     private ConnectionConsoleWindow connectionConsoleWindow = null;
     private PeersTableWindow mainFrame	= null;
-    private BlockChainTable blockChainWindow = null;
+    private BlockChainTable blockchainWindow = null;
     private WalletWindow walletWindow = null;
     private SerpentEditor serpentEditor = null;
 
@@ -71,7 +71,7 @@ public class ToolBar extends JFrame {
         addWindowListener(new WindowAdapter() {
             @Override
             public void windowClosing(WindowEvent e) {
-                WorldManager.instance.close();
+                WorldManager.getInstance().close();
             }
         });
 
@@ -182,13 +182,13 @@ public class ToolBar extends JFrame {
                     SwingUtilities.invokeLater(new Runnable() {
                         public void run() {
 
-                            if (blockChainWindow == null)
-                                blockChainWindow = new BlockChainTable(ToolBar.this);
-                            blockChainWindow.setVisible(true);
+                            if (blockchainWindow == null)
+                                blockchainWindow = new BlockChainTable(ToolBar.this);
+                            blockchainWindow.setVisible(true);
                         }
                     });
                 } else if (e.getStateChange() == ItemEvent.DESELECTED) {
-                    blockChainWindow.setVisible(false);
+                    blockchainWindow.setVisible(false);
                 }
             }
         });
@@ -226,9 +226,9 @@ public class ToolBar extends JFrame {
         cp.add(chainToggle);
         cp.add(walletToggle);
 
-        WorldManager.instance.getWallet();
-        WorldManager.instance.loadChain();
-
+        WorldManager.getInstance().getWallet();
+        WorldManager.getInstance().loadBlockChain();
+        
         MainData.instance.toString();
     }
 
diff --git a/ethereumj-core/src/main/java/org/ethereum/gui/WalletWindow.java b/ethereumj-core/src/main/java/org/ethereum/gui/WalletWindow.java
index 2a60a442..5ccbd4bf 100644
--- a/ethereumj-core/src/main/java/org/ethereum/gui/WalletWindow.java
+++ b/ethereumj-core/src/main/java/org/ethereum/gui/WalletWindow.java
@@ -41,7 +41,7 @@ public class WalletWindow extends JFrame implements Wallet.WalletListener{
         Container contentPane = this.getContentPane();
         contentPane.setBackground(new Color(255, 255, 255));
 
-        Wallet wallet = WorldManager.instance.getWallet();
+        Wallet wallet = WorldManager.getInstance().getWallet();
         wallet.addListener(this);
         loadWallet();
 
@@ -53,7 +53,7 @@ public class WalletWindow extends JFrame implements Wallet.WalletListener{
         contentPane.removeAll();
         contentPane.setLayout(new FlowLayout());
 
-        Wallet wallet = WorldManager.instance.getWallet();
+        Wallet wallet = WorldManager.getInstance().getWallet();
 
         for (Account account : wallet.getAccountCollection()) {
 			WalletAddressPanel rowPanel = new WalletAddressPanel(account);
@@ -73,7 +73,7 @@ public class WalletWindow extends JFrame implements Wallet.WalletListener{
             @Override
             public void mouseClicked(MouseEvent e) {
 
-                Wallet wallet = WorldManager.instance.getWallet();
+                Wallet wallet = WorldManager.getInstance().getWallet();
 				if (wallet.getAccountCollection().size() >= 5) {
                     JOptionPane.showMessageDialog(walletWindow,
                             "Hey do you really need more than 5 address for a demo wallet");
diff --git a/ethereumj-core/src/main/java/org/ethereum/manager/WorldManager.java b/ethereumj-core/src/main/java/org/ethereum/manager/WorldManager.java
index 11f3916b..031e019f 100644
--- a/ethereumj-core/src/main/java/org/ethereum/manager/WorldManager.java
+++ b/ethereumj-core/src/main/java/org/ethereum/manager/WorldManager.java
@@ -15,7 +15,6 @@ import org.ethereum.core.Transaction;
 import org.ethereum.core.Wallet;
 import org.ethereum.crypto.ECKey;
 import org.ethereum.crypto.HashUtil;
-import org.ethereum.db.DatabaseImpl;
 import org.ethereum.db.Repository;
 import org.ethereum.vm.Program;
 import org.ethereum.vm.ProgramInvoke;
@@ -39,22 +38,19 @@ public class WorldManager {
 	private Logger logger = LoggerFactory.getLogger("main");
 	private Logger stateLogger = LoggerFactory.getLogger("state");
 
-	private Blockchain blockChain;
-	private Wallet wallet = new Wallet();
+	private Blockchain blockchain;
+	private Repository repository;
+	private Wallet wallet;
 
 	private Map<String, Transaction> pendingTransactions = Collections
 			.synchronizedMap(new HashMap<String, Transaction>());
 
-	public DatabaseImpl chainDB = new DatabaseImpl("blockchain");
-	public Repository repository = new Repository();
-	
-	public static WorldManager instance = new WorldManager();
+	private static WorldManager instance;
 
 	public WorldManager() {
-	}
-
-	public void loadChain() {
-
+		this.blockchain = new Blockchain();
+		this.repository = new Repository();
+		this.wallet = new Wallet();
 		// Initialize Wallet
 		byte[] cowAddr = HashUtil.sha3("cow".getBytes());
 		ECKey key = ECKey.fromPrivate(cowAddr);
@@ -68,15 +64,25 @@ public class WorldManager {
 		wallet.importKey(cbAddr);
 
 		// Initialize Blockchain
-		blockChain = new Blockchain(wallet);
-		blockChain.loadChain();
+		blockchain.setWallet(wallet);
+	}
+	
+	public void loadBlockChain() {
+		this.blockchain.load();
+	}
+	
+	public static WorldManager getInstance() {
+		if(instance == null) {
+			instance = new WorldManager();
+		}
+		return instance;
 	}
 
 	public void applyTransaction(Transaction tx, byte[] coinbase) {
 
 		// TODO: refactor the wallet pending transactions to the world manager
-		if (blockChain != null)
-			blockChain.addWalletTransaction(tx);
+		if (blockchain != null)
+			blockchain.addWalletTransaction(tx);
 
 		// TODO: what is going on with simple wallet transfer ?
 
@@ -192,7 +198,7 @@ public class WorldManager {
 
 				byte[] initCode = tx.getData();
 
-				Block lastBlock = blockChain.getLastBlock();
+				Block lastBlock = blockchain.getLastBlock();
 
 				ProgramInvoke programInvoke = ProgramInvokeFactory
 						.createProgramInvoke(tx, lastBlock, trackRepository);
@@ -214,7 +220,7 @@ public class WorldManager {
 						.getReceiveAddress());
 				if (programCode != null) {
 
-					Block lastBlock = blockChain.getLastBlock();
+					Block lastBlock = blockchain.getLastBlock();
 
 					if (logger.isInfoEnabled())
 						logger.info("calling for existing contract: addres={}",
@@ -267,7 +273,7 @@ public class WorldManager {
 			bodyCode = result.getHReturn().array();
 		}
 
-		BigInteger gasPrice = BigInteger.valueOf(blockChain.getGasPrice());
+		BigInteger gasPrice = BigInteger.valueOf(blockchain.getGasPrice());
 		BigInteger refund = gasDebit.subtract(BigInteger.valueOf(
 				result.getGasUsed()).multiply(gasPrice));
 
@@ -316,8 +322,12 @@ public class WorldManager {
 		}
 	}
 
+	public Repository getRepository() {
+		return repository;
+	}
+	
 	public Blockchain getBlockChain() {
-		return blockChain;
+		return blockchain;
 	}
 
 	public Wallet getWallet() {
@@ -325,7 +335,7 @@ public class WorldManager {
 	}
 
 	public void close() {
-		chainDB.close();
+		blockchain.close();
 		repository.close();
 	}
 }
diff --git a/ethereumj-core/src/main/java/org/ethereum/net/client/EthereumProtocolHandler.java b/ethereumj-core/src/main/java/org/ethereum/net/client/EthereumProtocolHandler.java
index 1bd2e3ab..ece76d7b 100644
--- a/ethereumj-core/src/main/java/org/ethereum/net/client/EthereumProtocolHandler.java
+++ b/ethereumj-core/src/main/java/org/ethereum/net/client/EthereumProtocolHandler.java
@@ -254,7 +254,7 @@ public class EthereumProtocolHandler extends ChannelInboundHandlerAdapter {
                 }, 3000, secToAskForChain * 1000);
             }
 
-            WorldManager.instance.getBlockChain().addBlocks(blockList);
+            WorldManager.getInstance().getBlockChain().addBlocks(blockList);
             if (peerListener != null) peerListener.console(blocksMessage.toString());
         }
 
@@ -354,7 +354,7 @@ public class EthereumProtocolHandler extends ChannelInboundHandlerAdapter {
 
     private void sendGetChain(ChannelHandlerContext ctx) {
 
-        byte[] hash = WorldManager.instance.getBlockChain().getLatestBlockHash();
+        byte[] hash = WorldManager.getInstance().getBlockChain().getLatestBlockHash();
         GetChainMessage chainMessage = new GetChainMessage((byte)100, hash);
         chainMessage.toString();
 
diff --git a/ethereumj-core/src/main/java/org/ethereum/net/submit/TransactionTask.java b/ethereumj-core/src/main/java/org/ethereum/net/submit/TransactionTask.java
index d05c1905..c4d7326e 100644
--- a/ethereumj-core/src/main/java/org/ethereum/net/submit/TransactionTask.java
+++ b/ethereumj-core/src/main/java/org/ethereum/net/submit/TransactionTask.java
@@ -34,7 +34,7 @@ public class TransactionTask implements Callable<Transaction> {
 
             ClientPeer peer = MainData.instance.getActivePeer();
 
-			WalletTransaction walletTransaction = WorldManager.instance
+			WalletTransaction walletTransaction = WorldManager.getInstance()
 					.getBlockChain().addWalletTransaction(tx);
             peer.sendTransaction(tx);
 
@@ -44,7 +44,7 @@ public class TransactionTask implements Callable<Transaction> {
             logger.info("return approved: {}", walletTransaction.getApproved());
         } catch (Throwable th) {
             logger.info("exception caugh: {}", th.getCause());
-            WorldManager.instance.getBlockChain().removeWalletTransaction(tx);
+            WorldManager.getInstance().getBlockChain().removeWalletTransaction(tx);
         }
         return null;
     }
diff --git a/ethereumj-core/src/main/java/org/ethereum/trie/TrackTrie.java b/ethereumj-core/src/main/java/org/ethereum/trie/TrackTrie.java
index 24146b90..1b8749d9 100644
--- a/ethereumj-core/src/main/java/org/ethereum/trie/TrackTrie.java
+++ b/ethereumj-core/src/main/java/org/ethereum/trie/TrackTrie.java
@@ -24,8 +24,8 @@ public class TrackTrie implements TrieFacade {
 	}
 
 	public void startTrack() {
-		changes = new HashMap<ByteArrayWrapper, byte[]>();
-		deletes = new HashMap<ByteArrayWrapper, byte[]>();
+		changes = new HashMap<>();
+		deletes = new HashMap<>();
 		trackingChanges = true;
 	}
 
@@ -38,8 +38,8 @@ public class TrackTrie implements TrieFacade {
 	}
 
 	public void rollbackTrack() {
-		changes = new HashMap<ByteArrayWrapper, byte[]>();
-		deletes = new HashMap<ByteArrayWrapper, byte[]>();
+		changes = new HashMap<>();
+		deletes = new HashMap<>();
 		changes = null;
 		trackingChanges = false;
 	}
diff --git a/ethereumj-core/src/main/resources/system.properties b/ethereumj-core/src/main/resources/system.properties
index 993dcc75..a115d5fb 100644
--- a/ethereumj-core/src/main/resources/system.properties
+++ b/ethereumj-core/src/main/resources/system.properties
@@ -75,7 +75,7 @@ samples.dir = samples
 # the existing database will be 
 # destroyed and all the data will be 
 # downloaded from peers again
-database.reset = false
+database.reset = true
 
 # this string is computed
 # to be eventually the address
diff --git a/ethereumj-core/src/test/java/org/ethereum/core/BlockTest.java b/ethereumj-core/src/test/java/org/ethereum/core/BlockTest.java
index 7d68a0cf..8384fc33 100644
--- a/ethereumj-core/src/test/java/org/ethereum/core/BlockTest.java
+++ b/ethereumj-core/src/test/java/org/ethereum/core/BlockTest.java
@@ -3,7 +3,6 @@ package org.ethereum.core;
 import java.math.BigInteger;
 
 import org.ethereum.manager.WorldManager;
-import org.ethereum.util.ByteUtil;
 import org.spongycastle.util.encoders.Hex;
 import org.ethereum.core.Block;
 import org.ethereum.core.Genesis;
@@ -18,64 +17,11 @@ public class BlockTest {
 	private String CPP_PoC5_GENESIS_HEX_RLP_ENCODED = "f8abf8a7a00000000000000000000000000000000000000000000000000000000000000000a01dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347940000000000000000000000000000000000000000a08dbd704eb38d1c2b73ee4788715ea5828a030650829703f077729b2b613dd20680834000008080830f4240808080a004994f67dc55b09e814ab7ffc8df3686b4afb2bb53e60eae97ef043fe03fb829c0c0";
 	private String CPP_PoC5_GENESIS_HEX_HASH = "a7722d611450de26f55026b6544e34d9431b0a67a829e1794ac36fa4f079208f";
 
-	String block_1 = "f9072df8d3a077ef4fdaf389dca53236bcf7f72698e154eab2828f86fbc4fc6c"
-			+ "d9225d285c89a01dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0"
-			+ "a142fd40d493479476f5eabe4b342ee56b8ceba6ab2a770c3e2198e7a0faa0ca"
-			+ "43105f667dceb168eb4e0cdc98ef28a9da5c381edef70d843207601719a06785"
-			+ "f3860460b2aa29122698e83a5151b270e82532c1663e89e3df8c5445b8ca833f"
-			+ "f000018609184e72a000830f3e6f8227d2845387c58f80a00000000000000000"
-			+ "0000000000000000000000000000000094148d7738f78c04f90654f8c6f8a080"
-			+ "8609184e72a00082271094000000000000000000000000000000000000000080"
-			+ "b83a33604557602a5160106000396000f200604556330e0f602a59366000530a"
-			+ "0f602a596020600053013560005335576040600053016000546009581ca033a6"
-			+ "bfa5eb2f4b63f1b98bed9a987d096d32e56deecb050367c84955508f5365a015"
-			+ "034e7574ec073f0c448aac1d9f844387610dfef5342834b6825fbc35df5913a0"
-			+ "ee258e73d41ada73d8d6071ba7d236fbbe24fcfb9627fbd4310e24ffd87b961a"
-			+ "8203e9f90194f9016d018609184e72a000822710940000000000000000000000"
-			+ "00000000000000000080b901067f4e616d655265670000000000000000000000"
-			+ "00000000000000000000000000003057307f4e616d6552656700000000000000"
-			+ "000000000000000000000000000000000000577f436f6e666967000000000000"
-			+ "000000000000000000000000000000000000000073ccdeac59d35627b7de0933"
-			+ "2e819d5159e7bb72505773ccdeac59d35627b7de09332e819d5159e7bb72507f"
-			+ "436f6e6669670000000000000000000000000000000000000000000000000000"
-			+ "57336045576041516100c56000396000f20036602259604556330e0f600f5933"
-			+ "ff33560f601e5960003356576000335700604158600035560f602b590033560f"
-			+ "603659600033565733600035576000353357001ca0f3c527e484ea5546189979"
-			+ "c767b69aa9f1ad5a6f4b6077d4bccf5142723a67c9a069a4a29a2a315102fcd0"
-			+ "822d39ad696a6d7988c993bb2b911cc2a78bb8902d91a01ebe4782ea3ed224cc"
-			+ "bb777f5de9ee7b5bbb282ac08f7fa0ef95d3d1c1c6d1a1820ef7f8ccf8a60286"
-			+ "09184e72a00082271094ccdeac59d35627b7de09332e819d5159e7bb725080b8"
-			+ "4000000000000000000000000000000000000000000000000000000000000000"
-			+ "000000000000000000000000002d0aceee7e5ab874e22ccf8d1a649f59106d74"
-			+ "e81ba095ad45bf574c080e4d72da2cfd3dbe06cc814c1c662b5f74561f13e1e7"
-			+ "5058f2a057745a3db5482bccb5db462922b074f4b79244c4b1fa811ed094d728"
-			+ "e7b6da92a08599ea5d6cb6b9ad3311f0d82a3337125e05f4a82b9b0556cb3776"
-			+ "a6e1a02f8782132df8abf885038609184e72a000822710942d0aceee7e5ab874"
-			+ "e22ccf8d1a649f59106d74e880a0476176000000000000000000000000000000"
-			+ "00000000000000000000000000001ca09b5fdabd54ebc284249d2d2df6d43875"
-			+ "cb86c52bd2bac196d4f064c8ade054f2a07b33f5c8b277a408ec38d2457441d2"
-			+ "af32e55681c8ecb28eef3d2a152e8db5a9a0227a67fceb1bf4ddd31a7047e24b"
-			+ "e93c947ab3b539471555bb3509ed6e393c8e82178df90277f90250048609184e"
-			+ "72a0008246dd94000000000000000000000000000000000000000080b901e961"
-			+ "010033577f476176436f696e0000000000000000000000000000000000000000"
-			+ "000000000060005460006000600760006000732d0aceee7e5ab874e22ccf8d1a"
-			+ "649f59106d74e860645c03f150436000576000600157620f424060025761017d"
-			+ "5161006c6000396000f2006020360e0f61013f59602060006000374360205460"
-			+ "0056600054602056602054437f6e000000000000000000000000000000000000"
-			+ "00000000000000000000000000560e0f0f61008059437f6e0000000000000000"
-			+ "0000000000000000000000000000000000000000000000576000602054610400"
-			+ "60005304600053036000547f6400000000000000000000000000000000000000"
-			+ "0000000000000000000000005660016000030460406000200a0f61013e596001"
-			+ "60205301602054600a6020530b0f6100f45961040060005304600053017f6400"
-			+ "0000000000000000000000000000000000000000000000000000000000005760"
-			+ "20537f6900000000000000000000000000000000000000000000000000000000"
-			+ "000000576000537f640000000000000000000000000000000000000000000000"
-			+ "000000000000000057006040360e0f0f61014a59003356604054600035566060"
-			+ "546020356080546080536040530a0f6101695900608053604053033357608053"
-			+ "60605301600035571ba0190fc7ab634dc497fe1656fde523a4c26926d51a93db"
-			+ "2ba37af8e83c3741225da066ae0ec1217b0ca698a5369d4881e1c4cbde56af99"
-			+ "31ebf9281580a23b659c08a051f947cb2315d0259f55848c630caa10cd91d6e4"
-			+ "4ff8bad7758c65b25e2191308227d2c0";
+	String block_1 = "f8abf8a7a0000000000000000000000000000000000000000000000000000000"
+			+ "0000000000a01dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d"
+			+ "49347940000000000000000000000000000000000000000a08dbd704eb38d1c2b73ee47"
+			+ "88715ea5828a030650829703f077729b2b613dd20680834000008080830f4240808080a"
+			+ "004994f67dc55b09e814ab7ffc8df3686b4afb2bb53e60eae97ef043fe03fb829c0c0";
 	
 	String block_2 = "f8b5f8b1a0cf4b25b08b39350304fe12a16e4216c01a426f8f3dbf0d392b5b45"
 				   + "8ffb6a399da01dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a1"
@@ -169,8 +115,7 @@ public class BlockTest {
             assertEquals(new BigInteger(1, Genesis.DIFFICULTY), difficulty);
 
             // Storing genesis because the parent needs to be in the DB for calculation.
-            WorldManager.instance.chainDB.put(ByteUtil.longToBytes(Genesis.NUMBER),
-                    genesis.getEncoded());
+            WorldManager.getInstance().getBlockChain().addBlock(genesis);
 
             Block block1 = new Block(Hex.decode(block_1));
             BigInteger calcDifficulty = new BigInteger(1, block1.calcDifficulty());
@@ -179,20 +124,20 @@ public class BlockTest {
             System.out.println("Block#1 calculated difficulty = " + calcDifficulty.toString());
             assertEquals(actualDifficulty, calcDifficulty);
         } finally {
-            WorldManager.instance.close();
+            WorldManager.getInstance().close();
         }
     }
     
     @Test
     public void testCalcGasLimit() {
+    	WorldManager.getInstance();
     	Block genesis = Genesis.getInstance();
     	long gasLimit = genesis.calcGasLimit();
     	System.out.println("Genesis gasLimit = " + gasLimit);
     	assertEquals(Genesis.GAS_LIMIT, gasLimit);
     	
     	// Storing genesis because the parent needs to be in the DB for calculation.
-		WorldManager.instance.chainDB.put(ByteUtil.longToBytes(Genesis.NUMBER),
-				genesis.getEncoded());
+		WorldManager.getInstance().getBlockChain().addBlock(genesis);
     	
     	// Test with block
     	Block block1 = new Block(Hex.decode(block_1));