x1600 artifact problems

I've had my s96j for about 2 weeks now, and everything has worked fine until 2 days ago. I installed a couple new games (FEAR, Medal of Honor, and Far Cry) and defragged my hd, and when I woke up and started Medal of Honor, I found many serious artifacts and eventual freezing after about 30 seconds of gameplay (the game would lock up, then eventually turn into a windowed white screen and close itself). I fired up Oblivion, which had worked fine previously, and there were now artifacts in that too.

My temperatures had been a little higher than I would have liked ever since I got the laptop (around 52-55 idle), and now that I was having problems I decided to re-apply the AS5 and heatsink, which lowered my cpu idle temps to 48-52, but did not change the artifact problem.

Next, I tried to reinstall the drivers - first ATI then Omega, with no luck. I system restored to before I installed the games, but that didnt change anything either.

I reinstalled the catalyst drivers and went into the Powerplay settings to see if that could somehow be causing my problems. I turned the performance setting from "Performance Optimised" to "Balanced", and when I started Medal of Honor, there were no more artifacts. With ATI Tool, the 3d view failed after 10 seconds or so with "Performance Optimised", but ran find under the "balanced" setting, although the cube did not spin as smoothly.

What is enabled when I change to Optimum Performance that could cause artifacts in my games? Does it give the GPU more power, which could overheat it? I get the problem even when my system just booted and is under 35c, so I don't understand how it could be temperature. The fan does run almost constantly, however it is so low that I can barely hear it. Are there any applications to read the temps of an x1600 (atitools cant detect the x1600)?


Thanks for the help