Sound randomly dissappearing

Everything has been going well with this set up of mine. However, as of late my sound seems to be disappearing. As in, on first boot it works I can listen to music on iTunes or watch a video online and hear it all. Unfortunately, at a random interval all sound output stops. The sound preference panel shows the sound device still working however it outputs Zero sound. I does come back *sometimes* it generally takes a hard reboot for it to come back, logging out doesn't affect it. In my System Profile it doesn't show anything for built in Audio however in the Sound Preference pane it tells me it's a "AC97 Audio (PCM)" which correlates to my hardware correctly.

The board I'm currently using is a "ECS Nforce4M-A (Rev. 3) AM2" with "Realtek ALC655 6-Channel audio (AC'97)" on board. I didn't have to install any KEXT to get it to work, it worked "out-of-the-box".

Any clue what could be causing this?