I'm definitely inclined to believe it's the video card as well. It's an OEM from an Acer laptop. They haven't provided any driver support since its release so I've been forced to use Omega drivers to stay updated. I'm not sure how much of a factor that is. I did try rolling back to Acer's...
I just got this monitor two days ago and it works perfectly through VGA but when using DVI it blanks for a second about every few minute when doing something intensive like a game but hardly at all in windows. The rate of blanking increases the longer the game is running.
Some googling...