Well I have tried ANY settings combination that's available. That was ~ 3 weeks of testing and stressing. The conclusion i came is that when writing bandwidth excess a certain amount the system is unstable. That would be either a chipset fault or a memory incompatibility (?) Unfortunately i couldn't find any other P5Q-PRO owner with the sticks i tested (SUPERTALENT 800Mhz CL4, OCZ SLI EDITION 1066 CL5) to have a reference. Everyone seems to have corsair or g.skill or crucial..

I have contacted ASUS support and co-operated on researching the problem and they said me that maybe it's a Northbridge heat problem..

Also i have to mention that when i say "system unstable" i mean Prime95 blend. When using small ffts test there is no instability.. So that tells me that it's something to do with the memory. And because of the high fsb even lowering the memory to 1:1 and running it at 800Mhz doesn't lowers memory writing bandwidth..