Graphics Card Problems

[bridge86]

Im currently running a ATI Radeon 9000 Pro graphics card and I'm having some serious issues with playing Warcraft 3 at 1024x768x32 max settings. I get decent frame rates but After about 10 minutes or so into a game my screen goes black for a minute. When it recovers from that state it goes into a GPU recovery screen saying it has encountered a serious error and the GPU had to restart or something. The only remedy I've found is playing at an atrocious 800x600x16 with low everything but even that only lasts about an hour before i get the screen. My drivers are up to date and my GPU fan still works and is dusted. Any other suggestions to fix this problem.