Do you have a taskman shot? Could help, taskman and gpuz. The problem I had was that my card was severly underclocked by the drivers I treid first, and I only noticed when rt showed a 500/800/500 setting.
After installing the international download x64 vista drivers rt showed correct stock clocks and allowed oc'ing again, but I treid 3 diffrent downloads before that. The one which worked for me was NVIDIADisplayWinVista64(177_35)Int.exe size 81.408.768 bytes. The other two downloads both gave the same problem. Beta6 here though still btw idk why. If it aint broken don't fix it?
Edit: news belongs in this thread, but I don't want to make a big fuzz of it so this edit is all there will be.
http://www.xcpus.com/forums/folding-...e-nv-gpus.html ;)