Quote Originally Posted by Sasse View Post
Video card overheating wouldn't cause his entire system to shut down, would it?

Sounds to me more like an overheating cpu, or bad power supply.
if ANY component of a computer overheats it will shutdown as a safety measure for your computer. i had that problem with my old card. when my computer was shutting down, I just removed the cover and felt the card by touch when I was playing games. the card almost burned my finger, hot enough to fry bacon.