Actually my issue is more that the motherboard won't stay stable with anything more than 2gb in it. It's like the motherboard doesn't truly support the 4gb it claims it will. It will usually hang within 20s of power on, often less than 5s (just after post). Occasionally up to 15m. Specs: Asus P5n32-SLI Premium, Corsair XMS2-6400 1g sticks (4-4-4-12, 800mhz). BIOS updates haven't solved anything. OS doesn't matter, the machine will hang. 32 or 64 bit alike, Windows and linux. I do have dual GF 7950GTs connected via SLI in it, if that matters in any way. Also has a Core2 6600. Just trying to think of anything relevant that someone may look at me and say "You *******, this is your problem with it... and it has nothing to do with the problem at hand.."
It has been quite utterly infuriating to troubleshoot, as it's a hardlock, and leaves no relevant log info.