Well, when testing some E8600s on the RE I noticed often that I experienced a cold "boot" bug around -80 to -100 °C only few cpus were able to boot above -100 °C. In windows those -80°C cold boot bugs did something like -120 °C without any crashing. Annoying thing was everytime you powered off the mobo by changing some multiplier fsb or something like that in the bios u had to first cool down to -80 °C again to get it up running.
Other then that your problem sounds weird. I just used a delta to reach 646 fsb on the RE.