When I plug my iPod (2nd generation 40GB) into my iBook and open up iTunes the whole thing freezes. The multi-coloured wheel appears and it displays the iPod update screen. After some conciderable time a box appears stating that my iPod is being used by a different user. I can't force quit iTunes as it still believes that my iPod is connected. I have tried logging out from my username, restarting the iBook, switching the whole thing off, running the batteries down, reloading iTunes, and swearing at it but to no avail. The reasons it probably happened are that my girlfriend plug in her Nano on my user name, then unplugged it without ejecting. She also unplugged my iPod without ejecting after this. Any suggestions on how to fix this would be apreciated.