This has been happening to me quite often
I'm playing a game, either DOD or BF2 and about 15 minutes into it on most occasions my sound just cuts out and never comes back.
In the options, my sound isn't at the optimum levels so it should be fine. I never get this when listening to music or something.
I've just got an onboard soundcard by the way.
I know you guys can help me cause you did before.