iTunes freezes when ejecting ipod

I downloaded the latest version of iTunes a couple of days ago and the first time I coonected my iPod i got a message stating that a new driver was being downloaded. Then I got a message stating that the iPod was not recognised. After restarting my PC all seemed OK but when I eject my iPod (Nano 7) iTunes completely freezes and all I can do is restart my PC (Windows 7) to get it working again. This happens every time I try to use iTunes and eject my iPod.