I too have a dell laptop inspiron 1150. It worked fine with the IPOD for a while then same problem. I have a warranty. So I called apple and even got a repalcment ipod. The problem still persists. But since I have a new Ipod with the same problem, I have to think it is something to do with Dell. Not the drivers on the USB ports, but something about the compatability with the most recent Ipod firmware and Dell.

Please let me know if you find a solution.