Any users on my friends list have iPods? If so, HELP!!!

For no reason that I know of, my iPod mini stopped working today...I can sync it to my computer, use it with iTunes but the minute I disconnect it from my computer it will not respond. I've tried resetting it, and it works, then it just stops working again...I also tried restoring it to "factory settings" and that worked to, as long as it is connected to my computer. It says it is fully charged too. Any one ever have this problem before? Any ideas how to solve it?

HELP!!!!

Oh...and thank you for everyone who helped me with my YSI issues the other day :)