Do an experiment
Download VLC player (choose the nearest mirror site for download)...it's free & very reliable. I'm not any sort of music guru but I've just read a thread suggesting that downloading heaps of codecs for players can cause probs. VLC has it's own codecs built in.

So...download the player & then play one of the files that's been skipping with VLC. Open your saved folder outside of LW > right click on a file > open with > choose program > choose VLC.

See what happens then.