Kara:
I have a very similar setup,different ram and psu,both corsair. I have the 8800gts,p5ke 8400 ect. Roy is correct,reduce ram speed and loosen ram timing,the P5Ke seems to not like the 1066 ram speed even though it says it will handle it. I set mine to auto as well hasn't caused a prob since.... Your gonna luv the 8800 kinda overkill for AH2 tho... lol