Asrock P45XE will not respect my authority

(yeah I'm ripping off south park)

Anyway what I mean is that the BIOS just won't listen to me when I'm overclocking. To cut it short, basically once the settings get high the BIOS settings do not line up with actual results.

For example:

FSB 499MHz in BIOS, is 499Mhz in Windows. (awesome)
FSB 450Mhz in BIOS, is 450Mhz in Windows. (awesome)
FSB 451Mhz in BIOS, is 450Mhz in Windows. (wtf)
FSB 452Mhz in BIOS, is 450Mhz in Windows. (wtf)
this continues...
FSB 456Mhz in BIOS, and yey an increase to 451Mhz in Windows.

It's like 450-455 steps were skipped.

Raising the CPU voltage has the same issue, this seems to get worse with higher northbridge voltage settings.

Currently my CPU is set to 1.45V, if you go to BIOS hardware monitor, it shows VCore 1.412V, once in Windows its 1.38V no load and 1.36V under load.

Upside is I'm now running a 455FSB (set to 460 in BIOS) @ 1.38V (1.45V in BIOS).

Is this normal, or is this what I get for buying Asrock?

(upside is I'm stable (12 hour Prime95 torture test) on air at 4320Mhz, SuperPi 1M in 10 seconds )