I managed to reproduce it exactly once. After that time, mirc never did this again, even after reconnecting, restarting mirc and trying other little things (basically I tried repeating some of the things I'd done in my first session, like connecting to additional networks). It's weird.
Before anyone mentions it, that one time it happened, my current nick was not set to my altnick (it does happen in such cases, presumably intentionally).
Last edited by qwerty; 19/02/08 09:26 PM.