Aha, I'm glad i'm not the only one. I have conexant High Definition Audio on both machines that are giving the problem. Have you tried using a different driver yourself? I am reluctant to try to do that at the moment. I am wondering if in fact it is the sample rate being chopped too much when running on faster processors which has been overlooked?
the sound card drivers are the latest and no other program or app has this problem. As it appears to be a speed issue I was wondering if there is a throttle adjustment for the sound?