Are you using a battery backup with a line conditioner? Your machine could be receiving voltage spikes from the outlet where it's plugged in at.
HAF 932 case, Corsair HX1000 ps, APC BX1500LCD
Loop 1: EVGA x58 E760 i7 930, HK 3.0 cpu block, EK chipset block and dual bay res, swiftech mcp655 pump, feser xchanger 360 rad, scythe ultra kaze 4 fan controller w/kaze 3k fans, bitspower and feser fittings galore, distilled water w/primochill liquid utopia
Loop 2: Bitspower 150 res, feser x480 rad, scythe ultra kaze 4 fan controller and 3k fans, mcp655 pump with bp top, koolance uv blue tubing, evga gtx 480's with ek nickel plated blocks in parallel using koolance dual vid connectors, bp and feser fittings, distilled water w/primochill liquid utopia