I'm running Pidgin 2.9.0 on Fedora 15. In a specific IRC channel on a specific server, names are not removed from the list of people in the room in the GUI. As of this writing, I'm showing 71 people in a room, most duplicates. If I /part and /join the channel it drops (correctly) to 8. If instead I use /names it lists the names correctly.
I do get status messages when people enter or part the room, but not when they quit. I do not receive confirmation when I use /nick to change my username.
I am very, very confused. It works properly everywhere else.
This is a known bug in 2.9.0 and will be fixed in the next version.