When testing out overclocks on my new sabertooth mobo, I sometimes saw Windows giving my cpu a wrong frequency. I added it to the list of 'nice try windows' glitches and moved on.
Well that, Or I thought I was going crazy. Turns out I'm not:
http://hwbot.org/news/9824_breaking_windows_8_benchmark_results_no_longer_accepted_at_hwbot/
When I modified the 'HT reference clock', or the 'BCLK' or the 'fsb' speed (or whatever you wanna call it) - As opposed to the multiplyer - It turns out that were the situations were Windows 8 went bonkers. And as the article says, apperantly the problems go alot further than that!