i DID have the prob, flashed to f6, now no prob :-) reboots every time EXCEPT when i have voltage about 1.7, but i run 2.48 ghz @ 1.65 so i am safe, but to boot stable and do prime95 i have toi do 1.75 for 2.62 ghz, then i have reboot issues, so it looks like if voltage is <1.7 its cool :-)