Since I use iTunes Match, every few days iTunes restores some of my old playlists that I previously deleted. I think these are only the default playlists that iTunes comes with (Classical music, Music videos, Recently added, ...) but I'm not totally sure. At the same time, the "iTunes Match" link reappears in my sidebar, even though I can't do anything with it.
What triggers the reappearence of my old playlists? How can I prevent it and get rid of these playlists forever?