PC hardware forum: Video Card Problems

I've been having terminally severe problems with my video card. It's a relatively new Geforce GTX 275. My games keep crashing, even when running on minimum specs. This has been going on for a long time, and every single component of my computer has been replaced and upgraded at least once, but the problems persist and are always the same. The games I'm running aren't especially high-end and are reported to run fine on cards many grades lower than mine.

I'll use Fallout 3 as an example. At first, the game will run fine without a hint of lag. After a few minutes, the game will freeze for a brief moment, then return to normal. If I continue playing, the freezes become more frequent. Eventually the screen will go black for a moment, and when it returns, some textures or polygons will flicker, fly, or fail to render at all. Eventually, the game outright quits and I return to the desktop. After this, the computer will intermittently pause until I restart. It's happening every 30 seconds or so as I'm writing this post, which is really frustrating.

I'm not sure what temperature it should be, but I checked my card's temperature before playing (50-55 degrees), while playing (55-60 degrees), after the card spazzed (70-75 degrees), and after the game self-terminated (60-65 degrees). The temperature has returned to 50-55 degrees for now, and the picture is still freezing every so often. My CPU's temperature has held between 40-55 degrees the entire time, and is currently hanging around 48, so I doubt that's the issue.

In case it's relevant, I have Windows 7 x32 Home Premium, an Intel Core2 Quad CPU, an EVGA I780 motherboard, 4.8GB of extra RAM, and again my card is a Geforce GTX 275. Hope you guys can help. I'm really tired of this, and none of the forums I frequent could identify the problem. The best suggestion was air circulation, but the card isn't getting over 80 degrees. Is that enough for a GTX 275 to overheat?