Screen Scrambles?

While playing Counter-Strike sometimes my computer monitor will randomly scramble and I have to restart and rejoin to fix it. This is totally unexpected and I do not know how to fix it. I have a PNY GeForce 5200Ultra 128MB and the latest drivers from NVIDIA. If anyone knows what could fix this please help.

Just Counterstrike?

Approximately how long does it take?

Are you running anything in the background which might interfere?

Have you considered a heat problem? Have you inspected the card to make sure its fan is operational? If no fan, have you considered adding one?

Yes, just counter-strike, im not running any programs in the background that could interfere to cause this problem. It doesnt have a real set time its just pretty random