Weird problem on Windows XP - Skipping ??

I installed ultramixer demo and discovered a strange problem. When I play a song, be it on my hard drive, cd-rom or audio cd - the song will skip in a few places. More like a drop out, really.

I tried playing with the audio settings, but it did not seem to change things.

I have an HP with a Pentium 4 and m512 meg of memory. I am using an MAudio Delta 44 card.

This behavior does not happen on any other players.