I hate Nvidia drivers (IMO). Very buggy.
I have a PNY 5900 & I lose compatibility with Half-Life 2 if I try to use the BF2 demo driver or the current one.
I've been using the 71.89 driver and it is VERY stable (also IMO). I have not encountered a game that has crashed on me while using it. It is a little tricky finding the old Windows XP / 2000 drivers on Nvidia's site, but if you can find the archives (hint: GOOOOOGLE! it) you can find the 71.89 driver.
Combine that with NVtweak (coolbits 2.0) and you should be good to go.
Your card might be overheating, as to the crash. My 5900 is running at 450 / 900, vs stock 400 / 850 (with stock fan) and it does great in games, stability wise (performance is another story, that little prick hates Battlefield 2, and that is why I hate it right back. I have to play at 1024x768, medium textures, high texture filter (DO NOT PUT THE TEXTURE FILTER LOWER THAN HIGH IF YOU CAN, MAKES GAME MUCH HARDER!), no shadows, and low everything else to get good gameplay and FPS).
I used to have it at 450 / 950, but that pumps the ambient temperature (memory) up higher and I get artifacts frequently on heavy loads. When I down-clocked the memory to 900, it has not given me any complaints.