I have a problem with cod 4 ..... first 5 minutes is a joke...it stutters like mad....massive frame drop....it was ok with vista, but since installing windows 7 x64bit i have got this problem....any fixes for this?

Could this be the soundcard driver issue as i was getting bsod with a earlier version of w7 install?
Thought i had sussed it with my screen res being at 59hz instead of 60hz but sadly not.