I cannot figure this out, but when ever I playback music or MP3 music, using an MP3 player like Sonique I sometimes tend to get a dropout or pauses in the playback, they happen so very quickly, but its very noticable.
The faults would be like a split second pause, a scratchy sort of interference (like the CPU had been interrupted). I havent tried this playing back a CD, but it mainly happens with MP3 files. Also I'm running 2000 Pro, Pemtium III 500, 384MB RAM.