diff --git a/vendor/gems/mongo-1.1.4/lib/mongo/connection.rb b/vendor/gems/mongo-1.1.4/lib/mongo/connection.rb
index 68e7851..9aa49bf 100644
--- a/vendor/gems/mongo-1.1.4/lib/mongo/connection.rb
+++ b/vendor/gems/mongo-1.1.4/lib/mongo/connection.rb
@@ -431,11 +431,13 @@ module Mongo
         packed_message = message_with_headers.append!(message_with_check).to_s
         docs = num_received = cursor_id = ''
         @safe_mutexes[sock].synchronize do
-          send_message_on_socket(packed_message, sock)
-          docs, num_received, cursor_id = receive(sock)
+          close_socket_on_error(sock) do
+            send_message_on_socket(packed_message, sock)
+            docs, num_received, cursor_id = receive(sock)
+          end
         end
       ensure
-        checkin_writer(sock)
+        checkin_writer(sock) if sock && !sock.closed?
       end
 
       if num_received == 1 && (error = docs[0]['err'] || docs[0]['errmsg'])
@@ -462,11 +464,15 @@ module Mongo
 
         result = ''
         @safe_mutexes[sock].synchronize do
-          send_message_on_socket(packed_message, sock)
-          result = receive(sock)
+          close_socket_on_error(sock) do
+            send_message_on_socket(packed_message, sock)
+            result = receive(sock)
+          end
         end
       ensure
-        command ? checkin_writer(sock) : checkin_reader(sock)
+        if sock && !sock.closed?
+          command ? checkin_writer(sock) : checkin_reader(sock)
+        end
       end
       result
     end
@@ -927,5 +933,14 @@ module Mongo
         ""
       end
     end
+    
+    # When an exception occurs between a send/receive sequence or between
+    # receiving a header and a document, the client driver loses track of its
+    # place in the command stream. The socket must be closed.
+    def close_socket_on_error(socket)
+      yield
+    rescue Exception => exception
+      socket.close
+    end
   end
 end