The problem was with how the PlaylistDataManager manages the playlist.  When we used the full playlist message, it effectively recreated all of the entries, which meant it would have been a lot of effort to line up the entires that are already loaded, or in process of being loaded.  Which actually means there still may be a bug here when removing items that are being managed...but if anything it's a HD space resource leak, not a big issue like we had before.