Ipod Synchronization Failure

I have an iPod nano that is a few years old. It still works fine and has all my music & audio files, but I can no longer synch it with iTunes. I get an error "An iPod has been detected, but it could not be identified properly. Please disconnect and reconnect the iPod, then try again. If the problem persists, uninstall iTunes, then install iTunes again."

I re-tried a few times and uninstalled / re-installed iTunes as directed but I still get the same error. Anybody got any clues?