diff -ur dbus-1.2.12/dbus/dbus-connection.c dbus-1.2.12-patched/dbus/dbus-connection.c
--- dbus-1.2.12/dbus/dbus-connection.c	2008-08-07 20:44:36.000000000 +0200
+++ dbus-1.2.12-patched/dbus/dbus-connection.c	2009-02-10 23:23:32.000000000 +0100
@@ -2269,13 +2269,16 @@
 
   _dbus_assert (pending != NULL);
 
-  if (dbus_pending_call_get_completed (pending))
+  connection = _dbus_pending_call_get_connection_and_lock (pending);
+
+  if (_dbus_pending_call_get_completed_unlocked (pending))
+  {
+    CONNECTION_UNLOCK (connection);
     return;
+  }
 
   dbus_pending_call_ref (pending); /* necessary because the call could be canceled */
 
-  connection = _dbus_pending_call_get_connection_and_lock (pending);
-  
   /* Flush message queue - note, can affect dispatch status */
   _dbus_connection_flush_unlocked (connection);