Hi all... I can't seem to get my rig stable (Q9550@3.2GHz) with 8GB (2X4) ddr3 corsair vengeance low profile black. MOBO is Asus P5P43TD pro. It is unstable @ 1.5v @1600MHz. I have to set it at 1.6v - dropped it from 1.65v - was stable then decided different 2 months later!) CPU seems unaffected - any ideas? I am thinking PSU?