Kirby asks-

Is ActiveState's Pythonwin also incompatible with PyGeo then?

Was curious myself. The answer, yep. Quite incompatible. With the added attraction that I get the opportunity to notify Bill Gates of the problem when PythonWin closes down suddenly after closing a VPython window. Its all hard for me to understand. PythonWin is a Windows executable based on the scintilla library. And the behavior is as described. Scite is a Windows executable based on the scintilla library - and VPython windows shuts down quite politely. Were it not for that fact that VPython runs so smoothly on a number of other text editors I would conclude there is something fundamentally flawed in its design. Bruce Sherwood actually reported the problem of VPython running under the revised IDLE fork. It is actually quite ugly. Rather than a clean, but unwanted, shutdown that you get with the old IDLE, you get a deadlock and a window that is unresponsive in any way. Essentially an entire systems crash - as extensive of a crash as I've come across occuring under XP. It was acknowledged to be a bug. But I haven't seen anything subsequent in the messages or check-ins to indicate it has been fixed. Wish I understood more about what underlies all this - technically. Art