The other day I added code to my C/DirectX RPG so that it can run in a windowed mode as well as in fullscreen. It''s working well, except that every once in awhile upon closing, the program will generate an invalid page fault. What sort of error would cause this? It only happens maybe one in five times... I thought maybe I was doing something like using the window handle as a parameter after it was closed, or calling a method of a DirectX object after it had been released, and the only place I could think of where that could happen would be in my WindowProc(). So I added code to that function that logs the names of the messages which are not processed by DefWindowProc() as it receives them. I figured if I could run the program and get the IPF again, I could take a look at the log and see if maybe there were some messages passed to the window as it was shutting down that might be having this effect. But now I can''t recreate the error! I just ran the game 30 times and it didn''t cause an IPF once. Any ideas? Thanks! -Ironblayde Aeon Software