[MisterBenn]

I had some teething problems when I started out with this system - I had lockups in all games after a minute or so, usually reported as a video driver error and sometimes restarting my system. I chased around the guru3d.com forums for a long time without luck, until I finally cracked the problem. It was a CPU temperature issue! The stock cooler that came with the CPU was simply not up to the job and was overheating and causing the lockups.

The errors had all been misleading - I bought a large Akasa cooler and my system was immediately fixed for good. Are you the default cooler too? You might want try monitoring your temperatures if you haven't already...