Yep that works for a while. I thought it might be a fire wire thing, as my sound out is edirol fa101 fire wire, but it still gives the same problem with the onboard sound, which I disable when using edirol. One would expect the video to go first but that is rock steady, just sound cutting out every 5 secs or so. I have noticed that when thing start to go very bad the sound starts to distort as well, re boot time!
Asus p5b delux
2x 500g raptor raid
1T hd
500g system hd
4 gig ram
vista ultimate 64
matrox rtx2
radeon hd2900
coolmaster