Update...
I tried out overclocking my CPU today. I got up to 3Ghz with ease it seemed, just by increasing the FSB to 300Mhz from 200Mhz (leaving the multiplier at x10). I started to run Prime torture tests but stopped as I haven't stuck the temp probe in the case the CPU heatsink yet. I decided not to continue without be able to monitor the CPU temp, so I went back into the BIOS and put everything back to original settings.
Since then, when I run CPU-Z, I can see that the CPU doesn't seem to be underclocking itself now. Before it wold idle around 1600Mhz with a multiplier of x6 and shoot up when needed. Now it just constantly stays at 2667Mhz with a multiplier of x10.
Anyone know why????
Damien