I have the same exact problem with my RADEON 9600. I got the card about 3-4 months ago and thats when the problem started. I'm playing WarCraft III and all the sudden my screen freezes and this box says "Your video card stopped responding and the drivers had to be reset, please tell ATI about this problem" and sometiems it happens once-twice in 1 game. It lagged me out of the game before, because it took 30-60s to get back to the game, but since i got my new PCU it takes 10-30s.
I recently got a new mobo (ASUS P4P800 SE) replaced my old ASUS board and the problem still exists. I think it might be caused by my Video Card. I have the newest drivers and i also played around with the settings (set to max performance), but I still can't get rid of the problem.
Do you guys think its the Video Card that causes this??
AMD Athlon 64 3700+ San Diego @ 2.8GHz
DFI LanParty nf4 ultra-d
eVga 7800GT 256MB
1GB OCZ extreme series (2 x 512)
OCZ 550 Watt PSU
Samsung 200GB 7200rpm
Tsunami Dream Case