Can't run BLT program more than once?

I'm running activestate Python 2.4 for windows, and the latest BLT, under XP. I'm using pythonWin as my environment. When I run my plotting program the first time, it works just fine. If I exit out (normally), and then run it again from PythonWin, I get the following error. It's as if something

Can'r run BLT twice?

I'm running PythonWin on XP. When I run my plotter program the first time, it works fine. The second time I run it, I get the following error. If I exit PythonWin, and restart, I can again run it once. Any ideas? Error: 1 TclError Exception in Tk callback Function: bound method