I had my hard drive break, which lost all my music files. I recopied them from an old computer onto my new one with the new drive (most of the songs I had added by that point came from iTunes) and then it somehow got my new playlists and stuff from my iPod. For the few pieces it seemed to think were not in there, I searched out their location and highlighted the whole list and then right-clicked and selected "open with iTunes." That's one thing I hate about the whole ipod-itunes set-up. When I had other MP3 players before giving in and getting an iTouch, it was a simple matter of copying files from their folder on the computer to the device. There was none of this "trust Itunes to manage everything for you" and not knowing what is going on with the files and programs.