Normally I would just get lots of duplicates but lately it seems like songs that have been edited on one device then shared with other devices then sent to friends and mailed back with new changes will actually revert to an older version rather then add a 1 to it or two 11's or three 111's etc.

Another strange thing happened . I forgot about sync and emailed a set list to myself then ended up with two setlist (the emailed and the Synced) but they had identical names. A 1 was not added to the duplicate.
The only difference was for some reason one of them only had 7 songs in it and the other the full 29.

Songs are also just disappearing randomly from playlists .