Supafish, Have you tried higher qpi voltage? Also put ram on 1.65 and pll on the first notch=1.81 above you said you had qpiv set at 1.35, maybe try 1.4 or so I think this is the key to your oc, unless as T-flight says you have a bad cpu.
Dejanh, good job on the description of the problem to Asus:up: lets hope that fixes it.:)