iTunes cannot read the contents of the iPhone
If you connect your iPhone to iTunes and get the message "iTunes cannot read the contents of the iPhone," you can easily fix this by removing or renaming the /var/mobile/Media directory:
$ ssh root@iphone
$ mv /var/mobile/Media /var/mobile/Media.aside
$ rm -r /var/mobile/Media
After this you should be able to sync from iTunes again. Note that it will create the /var/mobile/Media hierarchy from scratch, and you will lose any music, videos, and photos currently on the phone.
From gtkpod - FAQ
My last backup was on the 9/9/10 so I lost about 3 weeks of data but I guess I didn't have to do a full restore.