intermittent buzzing sound on audio playback (ao522)

I've been having audio issues on a brand new 522-BZ465. Every so often during audio playback, a buzzing/distortion of the sound being played occurs. It isn't an issue with the speakers- the same distortion occurs when using headphones. The error isn't reproducible. Rewinding a section of audio after hearing the distortion will result in clear playback.

Tried updating the audio drivers, didn't help. Aside from that, the only differences between my laptop and a new one from the factory is a couple of downloaded programs(opera,utorrent,yahoo messenger). That's about it. Can't think of what might be causing the problem. is it a faulty soundcard?