MUC which have autojoin set are reopening itself even when I close them manually
I have number of MUCs which are actually IRC channels available via mod_irc at my ejabberd bookmarked and some of them have auto_join bit set.
One of them is
fedora%irc.freenode.net@irc.ceplovi.cz (which is unfortunately quite high volume one, so I quite often leave it when I have something more interesting to do). However, it always automatically opens after some time.