Sound Cutting Out

Taer

When I've been playing NS for a while (~30 min) my sound will randomly cut out. All sound from the game cuts out and interface sound in windows cuts out. I can still play media files via media player classic and hear them though. I have to restart my computer to get sound back and it always happens. I have an ASUS A7N8X Deluxe mobo with nForce 2 sound drivers. Does anyone have any idea what might be causing this and how to fix it?