Make sure you have the latest Nvidia Drivers, located here:
http://www.techsupportforum.com/641062-post1.html
And make sure you have the latest DirectX, located here:
http://www.microsoft.com/windows/directx/default.mspx
If neither of those help, download Everest from here:
http://www.majorgeeks.com/download4181.html
And SensorsView from here:
http://www.stvsoft.com/SensorsViewPro21Setup.exe
Use them to record your Temperatures and the voltages on your PSU - then post them here.
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"Come forth for the cattle call
Confront the evil river you can't control
Wicked ways and venomous eyes
Just human nature in disguise..."- Clouds over California