Ok so I need some help here. I'm overclocked to 4.2ghz. Temp max out at 65 on water. I've ran Prime stable for 26 hours (13 hours small FFT, 13 hours large FFT) rock ass solid. I can play every game I own, which is a lot. But the system crashes on both Crysis and Crysis Warhead and only those to games. Ive tried overclocking and underclocking the graphic cards. Ive tried it with GPU fans on max to rule out overheating of Cards (75 and 72 degrees on both cards GTX260 Sli) Ive tried restalling the game several times and no joy. Am I missing something?

Any help would be GREATLY appreciated.

System Info:
i7 920 D0 @ 4.2 ghz (1.26 V @ 21X200)
12 gigs Corsair RAM (9-9-9-24-2t set loose to help with 6 stick overclock)
GTX 260 core 216 Sli

Motherboard settings set to jasonelmore's recommendations.