Hi Nemisis, I agree with dethblud, when I run my O/Cl'ed celery to the max 466Mhz Poser runs like Sh$%!, if fact it is unustable, when I reduce the O/C speed to 450Mhz it's stable. I think this is something to do with memory access, possible a memory module is slighty damaged and pushing it to the max causes crashes. Try reducing by a few Mhz...it sucks I know but it may be the only way... PeACE, Good Luck, Tribe.