It seems to solve the problem. What I did:
def contextDataHandler(self): self.contextdata.process_busy=True self.services.findServices() self.drawDisplay() self.contextdata.process_busy=False def doCallback(self): self.at.cancel() if self.process_busy==False: self.at.after(0.01,self.data_callback) The app works awesomely stable now data_callback refers to contextDataHandler in parent class Thanks guys, good job -- http://mail.python.org/mailman/listinfo/python-list