I have a NVIDIA GeForce GT 430 Card, and recently the card has been shutting off when I play games (TrackMania2, Gotham City Impostors, Just Cause 2). I downloaded SpeedFan, and it turns out that the temperatures get up to 100 C. The weird thing is that within 3 seconds of switching out of the game, it will drop 15 degrees almost instantaneously. I've tried cleaning out the card, and downloading the latest drivers, but it only made a marginal difference, it still shuts down periodically.