Well, it would seem that there's some sort of crash exploit for mIRC 6.12, but I don't know what it is as I woke up to a crash dialog.
Mightn't it be a nice idea if mIRC had the option to save a constantly updated crash.log which consisted of the last 10kb of raw data mIRC received/sent? That way we might be able to better analyse what caused mIRC to crash.