The reported multiplier can get a little jumpy on some motherboards when running monitoring software that samples a lot of voltages. HW Monitor and Everest sometimes cause problems.

I know ben805 had to raise his core voltage with bios 0006. When the turbo was throttling and dropping down to 20X at full load, it obviously didn't need as much core voltage to remain stable. With bios 0006, his multiplier was now steady at 21X at full load so extra core voltage was necessary to remain stable.

I think EIST has to be enabled to get the Minimum processor state option available in the Power Options. If you can't boot up with that set then I understand that's not an option for you.