Almost the exact same behavior I’m seeing in Openfire 3.6.3 was reported here: http://www.igniterealtime.org/community/message/137188#137188
I also submitted a bug with pidgin: http://developer.pidgin.im/ticket/9537
Essentially the problem is that it is possible to create two chat rooms of the same name, but with different case. (e.g. “room” and “ROOM”) When some clients attempt to join “ROOM” they are sent to “room” but any attempts to send chat result in a “Code 406” error. Joining “room” with these clients results in normal behavior.
Via the Admin webinterface it is not possible to create these duplicate case-differentiated rooms. I’ve only been able to create “duplicate” rooms directly via the client.
Although “ROOM” will show up in the “Group Chat” interface on the server any attempt to modify the settings actually results in changes being made to “room”. Deleting “ROOM” via the inteface properly destroys “ROOM” without affecting “room”.
Message was edited by: Alex - fixing typo, code is 406, not 404