I had simalar problems about a year ago and the response that I got from this forum was that I needed to turn down the soundcard and run DX to make sure that it would load properly. Click start go to run, type in dxdiag and then start the the DX program make sure that it is loaded properly. Go to the soundcard portion and check you settings. I wound up chaging things slightly and now I haven't had the problems.
I hope this helps.
I have no idea why this posted this way. Cheek I am sorry but the site doesn't seem to want to coorperate with me today.