[PyKDE] sys.exit() locks XP QT4

[Dave S]

I used to exit my program with sys.exit() in Linux but in XP the 
method ...

    @QtCore.pyqtSignature("")
    def on_action_Exit_activated(self):
        # File Exit
        sys.exit()

locks my app with a permanent hour glass, If I try & right click close on the 
taskbar I get 'program not responding', 'send error report to Microsoft' etc 
etc

How do you guys exit cleanly in XP Qt4 ?