Daughter's iPod won't sync with iTunes

First of all, let me get this confession out of the way - I'm a Windows PC users, and all of this Apple stuff is totally foreign to me. We got our daughter an iPod Nano for Xmas, and so far it has been working fine. However, yesterday when she put some new songs on iTunes and tried to sync with her iPod, it didn't work. The computer recognized the device (it made the "ping" sound and flashed up the contents of the iPod), but the iPod wouldn't connect with iTunes. I tried uninstalling and reinstalling the software - no dice. I get error messages that clearly indicated iTunes is not locating the iPod.

Can anyone help a stranger in a strange land? I am running a PC with MS XP Pro, Service Pack 2.

Many Thanks!!