Tiny, my iPod did the exact same thing. I did everything everyone else mentioned on here, it eventually stopped.
Its new trick, however, is that it changes languages, randomly. Today, we're cool, English. Last week? French. Two days ago? German. Well, I thought it was German but the helpful hispter at the Apple store politely informed me that no, it was Dutch. Oh! Okay!
Anyway, they said these random things do happen with some of them, but since I had it longer than a year, they can't do anything. I was frustrated and just let it go, I should have tried harder.
I recommend getting them to do something ASAP before your skipping turns into skipping in Japanese. Tell them about horror stories you've heard. Try for some easily-intimidated Apple store person who might be swayed.
Good luck.