Have you been able to reproduce it yet?
Have you guys been able to reproduce the problem yet?
I'm willing to bring the machine over to you guys to play with for a few days to help solve the problem, if that would help (you'd be free to wipe the harddrive, etc)
Offscreen rendering is uneffected by the corruption.
When you get it into this state, you can open up a new window, and certain parts of the new window (most/all of the background part of the window) will be transparent. i.e. black text will appear as black, but as if the window's canvas was translucent.
The screenshot was taken on RH9.0 running kernel 2.4.20-9smp, using 4349