My understanding is that it usually occurs whenever a daemon is unable to shut down correctly, so it locks up the entire process of shutting down. The networki

My understanding is that it usually occurs whenever a daemon is unable to shut down correctly, so it locks up the entire process of shutting down. The networking daemons were what used to cause it when I had Fedora installed, iirc. I would start looking there. As for why it's so vague and self contradictory, I couldn't say.