i've been using my 6th gen nano for a few months now with no problems. suddenly today, i plugged it in and it wasn't recognized by windows and doesn't show up in itunes.
i keep getting errors stating the unknown device is not recognized. i've uninstalled and reinstalled drivers in the Device Manager. i've tried everything on this support page: http://support.apple.com/kb/TS1538. i've also uninstalled, reset, and reinstalled itunes...twice. i've also reset the 6th gen nano several times by holding down the - volume button and sleep button.
the weird thing is, when i plug in my 2nd gen shuffle, it's instantly recognized by win7 and itunes. same thing for my 1st gen nano (using the same cable and USB port).