diff --git a/github/Github.py b/github/Github.py
index 12eacfd9..f6d4acf4 100644
--- a/github/Github.py
+++ b/github/Github.py
@@ -23,6 +23,7 @@ class Github( object ):
                 None,
                 None
             )
+            NamedUser.NamedUser._checkStatus( status, data )
             return NamedUser.NamedUser( self.__requester, data, completed = True )
 
     def get_organization( self, login ):
@@ -32,6 +33,7 @@ class Github( object ):
             None,
             None
         )
+        Organization.Organization._checkStatus( status, data )
         return Organization.Organization( self.__requester, data, completed = True )
 
     def get_gist( self, id ):
@@ -41,10 +43,12 @@ class Github( object ):
             None,
             None
         )
+        Gist.Gist._checkStatus( status, data )
         return Gist.Gist( self.__requester, data, completed = True )
 
     def get_gists( self ):
         status, headers, data = self.__requester.request( "GET", "https://api.github.com/gists/public", None, None )
+        Gist.Gist._checkStatus( status, data )
         return PaginatedList.PaginatedList(
             Gist.Gist,
             self.__requester,
diff --git a/github/GithubObject.py b/github/GithubObject.py
index 485d345a..fe772774 100644
--- a/github/GithubObject.py
+++ b/github/GithubObject.py
@@ -13,14 +13,17 @@ class BasicGithubObject( object ):
     def _request( self, verb, url, parameters, input ):
         return self._requester.request( verb, url, parameters, input )
 
-    def _parentUrl( self, url ):
+    @staticmethod
+    def _parentUrl( url ):
         return "/".join( url.split( "/" )[ : -1 ] )
 
-    def _checkStatus( self, status, data ):
+    @staticmethod
+    def _checkStatus( status, data ):
         if status >= 400:
             raise GithubException.GithubException( status, data )
 
-    def _NoneIfNotSet( self, value ):
+    @staticmethod
+    def _NoneIfNotSet( value ):
         if value is NotSet:
             return None
         else:
@@ -42,5 +45,6 @@ class GithubObject( BasicGithubObject ):
             None,
             None
         )
+        self._checkStatus( status, data )
         self._useAttributes( data )
         self._completed = True
diff --git a/github/PaginatedList.py b/github/PaginatedList.py
index d2af8b7c..8ca566f7 100644
--- a/github/PaginatedList.py
+++ b/github/PaginatedList.py
@@ -1,3 +1,5 @@
+import GithubObject
+
 class PaginatedList:
     def __init__( self, contentClass, requester, headers, data ):
         self.__requester = requester
@@ -49,6 +51,7 @@ class PaginatedList:
 
     def __fetchNextPage( self ):
         status, headers, data = self.__requester.request( "GET", self.__nextUrl, None, None )
+        GithubObject.GithubObject._checkStatus( status, data )
         return self.__appendData( headers, data )
 
     def __appendData( self, headers, data ):
diff --git a/github/Requester.py b/github/Requester.py
index ef14244d..d62b5c19 100644
--- a/github/Requester.py
+++ b/github/Requester.py
@@ -39,7 +39,8 @@ class Requester:
 
         cnx.close()
 
-        self.rate_limiting = ( int( headers[ "x-ratelimit-remaining" ] ), int( headers[ "x-ratelimit-limit" ] ) )
+        if "x-ratelimit-remaining" in headers and "x-ratelimit-limit" in headers:
+            self.rate_limiting = ( int( headers[ "x-ratelimit-remaining" ] ), int( headers[ "x-ratelimit-limit" ] ) )
 
         # print verb, url, parameters, input, "==>", status, str( headers )[ :30 ], str( output )[ :30 ]
         return status, headers, output
diff --git a/test/Exceptions.py b/test/Exceptions.py
index 677145e1..da920ec2 100644
--- a/test/Exceptions.py
+++ b/test/Exceptions.py
@@ -2,9 +2,10 @@ import github
 
 import Framework
 
+# To stay compatible with Python 2.6, we do not use self.assertRaises with only one argument
 class Exceptions( Framework.TestCase ):
     def testInvalidInput( self ):
-        try: # Stay compatible with Python 2.6: do not use self.assertRaises with only one argument
+        try:
             self.g.get_user().create_key( "Bad key", "xxx" )
             self.fail( "Should have raised" )
         except github.GithubException, exception:
@@ -24,3 +25,30 @@ class Exceptions( Framework.TestCase ):
                 }
             )
             self.assertEqual( str( exception ), "422 {u\'message\': u\'Validation Failed\', u\'errors\': [{u\'field\': u\'key\', u\'message\': u\"key is invalid. It must begin with \'ssh-rsa\' or \'ssh-dss\'. Check that you\'re copying the public half of the key\", u\'code\': u\'custom\', u\'resource\': u\'PublicKey\'}]}" )
+
+    def testUnknownObject( self ):
+        try:
+            self.g.get_user().get_repo( "Xxx" )
+            self.fail( "Should have raised" )
+        except github.GithubException, exception:
+            self.assertEqual( exception.status, 404 )
+            self.assertEqual( exception.data, { "message": "Not Found" } )
+            self.assertEqual( str( exception ), "404 {u'message': u'Not Found'}" )
+
+    def testUnknownUser( self ):
+        try:
+            self.g.get_user( "ThisUserShouldReallyNotExist" )
+            self.fail( "Should have raised" )
+        except github.GithubException, exception:
+            self.assertEqual( exception.status, 404 )
+            self.assertEqual( exception.data, { "message": "Not Found" } )
+            self.assertEqual( str( exception ), "404 {u'message': u'Not Found'}" )
+
+    def testBadAuthentication( self ):
+        try:
+            github.Github( "BadUser", "BadPassword" ).get_user().login
+            self.fail( "Should have raised" )
+        except github.GithubException, exception:
+            self.assertEqual( exception.status, 401 )
+            self.assertEqual( exception.data, { "message": "Bad credentials" } )
+            self.assertEqual( str( exception ), "401 {u'message': u'Bad credentials'}" )
diff --git a/test/ReplayData/Exceptions.testBadAuthentication.txt b/test/ReplayData/Exceptions.testBadAuthentication.txt
new file mode 100644
index 00000000..084559c4
--- /dev/null
+++ b/test/ReplayData/Exceptions.testBadAuthentication.txt
@@ -0,0 +1,5 @@
+GET /user {'Authorization': 'Basic login_and_password_removed'} null
+401
+[('status', '401 Unauthorized'), ('content-length', '29'), ('server', 'nginx/1.0.13'), ('connection', 'keep-alive'), ('etag', '"ca6a3702f840b6bff0bb1bca6be0337c"'), ('date', 'Sat, 02 Jun 2012 12:12:32 GMT'), ('content-type', 'application/json; charset=utf-8')]
+{"message":"Bad credentials"}
+
diff --git a/test/ReplayData/Exceptions.testUnknownObject.txt b/test/ReplayData/Exceptions.testUnknownObject.txt
new file mode 100644
index 00000000..9d3f7c1d
--- /dev/null
+++ b/test/ReplayData/Exceptions.testUnknownObject.txt
@@ -0,0 +1,10 @@
+GET /user {'Authorization': 'Basic login_and_password_removed'} null
+200
+[('status', '200 OK'), ('x-ratelimit-remaining', '4971'), ('content-length', '801'), ('server', 'nginx/1.0.13'), ('connection', 'keep-alive'), ('x-ratelimit-limit', '5000'), ('etag', '"0e6c8f1cbb0c4f0eae96d8a76de9a43f"'), ('date', 'Sat, 02 Jun 2012 12:11:46 GMT'), ('content-type', 'application/json; charset=utf-8')]
+{"type":"User","total_private_repos":5,"company":"Criteo","gravatar_id":"b68de5ae38616c296fa345d2b9df2225","login":"jacquev6","public_gists":3,"email":"vincent@vincent-jacques.net","owned_private_repos":5,"avatar_url":"https://secure.gravatar.com/avatar/b68de5ae38616c296fa345d2b9df2225?d=https://a248.e.akamai.net/assets.github.com%2Fimages%2Fgravatars%2Fgravatar-140.png","private_gists":5,"collaborators":0,"created_at":"2010-07-09T06:10:06Z","blog":"http://vincent-jacques.net","location":"Paris, France","url":"https://api.github.com/users/jacquev6","following":24,"disk_usage":16988,"public_repos":10,"name":"Vincent Jacques","hireable":false,"followers":13,"html_url":"https://github.com/jacquev6","id":327146,"plan":{"private_repos":5,"collaborators":1,"space":614400,"name":"micro"},"bio":""}
+
+GET /repos/jacquev6/Xxx {'Authorization': 'Basic login_and_password_removed'} null
+404
+[('status', '404 Not Found'), ('x-ratelimit-remaining', '4970'), ('content-length', '23'), ('server', 'nginx/1.0.13'), ('connection', 'keep-alive'), ('x-ratelimit-limit', '5000'), ('etag', '"e66a7a6c91e2c26803f3f49feb7a883f"'), ('date', 'Sat, 02 Jun 2012 12:11:47 GMT'), ('content-type', 'application/json; charset=utf-8')]
+{"message":"Not Found"}
+
diff --git a/test/ReplayData/Exceptions.testUnknownUser.txt b/test/ReplayData/Exceptions.testUnknownUser.txt
new file mode 100644
index 00000000..c41ea245
--- /dev/null
+++ b/test/ReplayData/Exceptions.testUnknownUser.txt
@@ -0,0 +1,5 @@
+GET /users/ThisUserShouldReallyNotExist {'Authorization': 'Basic login_and_password_removed'} null
+404
+[('status', '404 Not Found'), ('x-ratelimit-remaining', '4968'), ('content-length', '23'), ('server', 'nginx/1.0.13'), ('connection', 'keep-alive'), ('x-ratelimit-limit', '5000'), ('etag', '"e66a7a6c91e2c26803f3f49feb7a883f"'), ('date', 'Sat, 02 Jun 2012 12:24:43 GMT'), ('content-type', 'application/json; charset=utf-8')]
+{"message":"Not Found"}
+