Sony :: BSOD's While Overclocking

I have a FW-550 F/B (specs here: [url]. I want to overclock it to 600/800. After using Riva Tuner to set the clocks, I always run a FurMark stability test (1280x1024, 4xAA), while monitoring the temps with GPU-Z. It always crashes to a black screen (the monitor doesn't turn off, I just stop hearing anything and later I get a loud buzzing noise). The only solution is to do a hard reboot.

- It's not a temp. problem, sometimes it crashes at 60C, sometimes at 70C

- The GPU is not faulty, at normal clocks I beat Far Cry 2, Dead Space, RE5, Crysis, and Fallout 3 at pretty high settings without a single crash. All those games push the GPU load to 100% and temps go up to nearly 70C.

Some interesting things

- I had this problem in Mass Effect at normal clocks. I lowered the settings until it was almost pixelated but it persisted. I did some research and it seems i wasn't the only one, so I stopped playing the game until I could find a solution

- After this problem, I checked the Event Viewer. Apparently, they're all bluescreens. The description says "Display is not active'", with the source being "atikmdag.sys "

Maybe it's a driver issue?