Hello, I am going start raving mad on this.
I have an A8N SLI Premium mobo, AMD Opteron 170, 2x 1Gb Mushkin Extreme DDR 400 RAM, GeForce 6800GS Video Card, and a PSU rated at 500W providing 17A for the 12V line.
All was fine for about a month of use.
I was using the PC for transcoding videos...