Westsideplaya - I'm getting something similar in memory perfromance around 1200, but not as marked:

As set in bios
1200mhz 5-5-5-18 Everest mem latency: 44.7, mem read: 11786
1227mhz 5-5-5-18 Everest mem latency 45.7, mem read 11660
Boot at 1200 then raise FSB so mem at 1227 gives latency 43.5, mem read 12101

Jeremy 617 - have you checked those voltages with a volt meter? I was under the impression that CPUID was usually pretty accurate (something I could easily be wrong about).