A single Thread Crashes

[ian]

I create a wxPython Window app with a 1-second timer displaying clock on status bar, and a 5-minute timer running a function called Update1 every 5 minutes to download data and update a wx.Grid. I also add time.sleep in different places as need.
When using a single Thread to run Update1 every 5 minutes, it crashes during update, saying 'Not responding..'.
Will timer or sleep cause the crash? any solution? Thanks.