Try: -Reset ipod (home plus on off) -diff computer -try an older usb cable from an older ipod version.
Ok, I'm uninstalling iTunes then reinstalling iTunes to see if that will work. If that doesn't work I'll reset it, if that doesn;t work I'll try a different computer,then if that doesn' work I'll call Apple. EDIT: uninstalling iTunes then reinstalling iTunes worked.
Good to see it already worked out for you. I had a similar problem but that was sorted out with a simple restart of the computer and iPhone both.