iPod Nano not recognized in iTunes, desktop, iPod reset

I went to update my iPod Nano's music selection and found it isn't showing up in iTunes. I reinstalled iTunes, restarted the computer, reset the Nano and still nothing. It does not show up in Disk Utility but does show up in Apple Disk Profiler. When I try the iPod updater, it says "waiting for the iPod to be ready". My 30 GB iPod works just fine, immediately recognized by iTunes. As soon as I connect the iPod Nano to the computer, it goes to "Do not Disconnect", darkens, and stays there. It does charge. How can I reformat the Nano if iTunes or iPod updater doesn't see/recognize it?