I have my Q9550 oc'd to 3.6Ghz on a Nvidia 750i mobo. It is completely stable (2 hours Prime95, Large FFT's, Intel Burntest, 4 hours gaming and not a single problem), the max temp is about 52c on all 4 cores. I can run it all day and restart numerous times without a problem, but then i shutdown and it will not post when i turn it back on. I'm stumped. Any suggestions?