Are you using the LW player? If so, try disabling the LW player (tools > options > player) & using something else... does the same thing happen?
The LW player's not good, it can really suffer if you're uploading or downloading while trying to play songs

I'd recommend disabling it permanently & using another player.
If you're looking for a player, try VLC. It's free, reliable & plays most file types. Check the link here for info about VLC & other players:
http://www.gnutellaforums.com/tips-t...p3-fixers.html