Ok this used to happen to me. I searched on Google and found this discussion on the Apple site. "
REEEAAAD MEEEE!!!
Alright so this just happened to my iPod and I spent like two hours trying to figure it out and I finally did. It's totally simple, by the way.
It won't charge because it doesn't have enough juice to start charging [crazy as that sounds] so it just continually resets it's self. You need to have it hooked up to your computer in 'disk mode'.
1. Take your iPod and plug it in to your USB port.
2. Hold down the select [center button] and the play button.
That's it, It might have to update your library but you shouldn't lose all your music. It worked for me so I'm hoping it can solve all of your guys' problems too. Good luck!"
It was from someone who posted by the name of Mr. Orange. Anyway, maybe try this?
Here is the site if you want to look at other responses.
http://discussions.apple.com/thread.jspa?messageID=7090221