Video accelleration problems after playing a game

[onexused]

Sometimes, after running a certain buggy game under wine, X starts to perform some actions very slowly. For examples:
- Starting an OpenGL screensaver (I need to test this still with a non-OpenGL screensaver) will take many minutes: the screen fades to black, each step taking 30+ seconds. Moving the mouse has no effect during this, but doing so after the screensaver has started will cause the screensaver to freeze for about 10 seconds before showing the desktop.
- Switching to (but not away from) tty7 (ctrl+alt+F7) freezes the display for a noticeable length of time before showing the desktop.
- Alt-tabbing between certain applications (zsnes and something else, for example), causes the display for freeze for a few seconds before performing the action. X often thinks the mouse button is still held down afterward if I clicked the window instead of alt-tabbing.
- CPU usage jumps for any program or game that uses hardware video acceleration after this happens. As well, these programs and games run more slowly, as if I had a worse video card.

I can't reproduce this issue at will. However, running the game several times or for several hours has a good chance of producing the issue.
Restarting X doesn't help. Removing and reprobing the nvidia module while X is down doesn't help. After doing this and restarting X, I get the nvidia logo 3-4 times (I normally don't get it when starting X) before X starts.

How do I either stop this from happening in the first place or fix it when it does happen? Rebooting fixes this problem until the next time it happens, but I feel I shouldn't have to reboot.
I'm using an nvidia 8600GT video card with nvidia-drivers-260.19.21
tuxonice-sources-2.6.36-r1 with USE="-deblob"
wine-1.3.7 (this has happened for several recent wine versions)