I converted an old free account to a new premium family account. I also had another, more recent free account, and from there I dragged playlists to the desktop and imported them into the new family account. They show there and play OK. But when I try to drag new songs into these imported playlists they grey out. If I right click and select 'add to playlist', only the playlists that were in the old free account show up and my imported ones are missing from the list.