I suggest that you set ACC to +4 for all cores to start. I think you may have a flakey core that needs a specific ACC setting. Also, turn off cpu tweak in the bios. This will reduce core heat and maybe give you a minor bump in stability.

My gpu fan also starts high at boot and then drops. Must be a power management issue with the bios, I am on 0602.

Glad you are back Kas, we missed you!