1 With File locations "Sync files to:" Music: [b]Curtains\$Replace(<Path:-2>,\,-)[/b], auto-sync a playlist
2 Change "Sync files to:" Music: to [b]Curtain\$Replace(<Path:-2>,\,-)[/b] (removed "s")
3 Rename HD folder Curtains to Curtain
4 Add files to playlist
5 Auto-sync

Expected: all playlist references to new location Curtain
Observed: some playlist references to new location Curtain, others old new location Curtain, hence broken: http://i.imgur.com/sChNvOk.png

It seems MM has failed to clear out-of-date data from some cache. "Optimize database (Complete)" does not remedy this.

Anyone know a workaround? E.g. where it the DB to delete this bad data?

EDIT: Workaround: check "[x] Enforce use of sync mask for files already on the device"