[Hugh R]

No expert here, but I've had that happen before and hit "restore" and then reloaded the stuff from the puter back to the iPod. Restore brings the iPod back to factory settings. Re-syncing brings all you junk back to the iPod.

Wait for opinions from others more knowledgable than me before doing the "Nuclear" option.

If you don't have Carbonite, or one of the other offsite backups, you should, it backs up musiic as well.