I don’t think this was reported yet, but I couldn’t find it when looking through all the threads here. When somebody changes their nick in IRC, the transport doesn’t seem to pick up on it. So until you rejoin the channel, it thinks the person is still known by their original nick (even though messages come from the new nick). If I check the list of people in the room, I also still see the old nick, rather than the new one.
MysticOne