@Cryptik & 64DRAGON,
Sounds like a plan...thanks guys, I'll pick up some AS-Ceramique or Shin Etsu tomorrow and re-seat the NB heatsink and see if the temps get better.
Any ideas on the OC potential of my RAM (8GB Mushkin DDR2 800 6400)..? At the moment I've got it running at 5.5.5.15 2T @400.8 MHz on 5:6, The timings seem to be twitchy and having tried some of the timings I've seen other people use I don't get a boot.