Yeah I had something similar happen to me but it was way back when a geforce 2 Mx was a good card... ok I lied, it was never good.
Anyway, my monitor spat out a bunch of different colors at different times and I tried messing with it, then it just fried (the card). So I sent it back in, and (thank the Lord for this) I recieved an even BETTER card in its place. An ATI Rage 32MB! Gotta love tigerdirect. Idiots.
Back to the point, the problem was fixed with the new card, but instead of mailing it back to get the right card, I just upgraded to the geforce 3 ti 500, which has been in my pc ever since. And I haven't had the problem again.