Could you test this on another network too, e.g. EFNet, QuakeNet, Undernet.
Justin.tv is an IRC network that follows the IRC protocol loosely (iirc).
I see that in raw 474 it does not return the channel name with a hash sign in front of it, which *may* cause mIRC to not update the channel status correctly.
Yeah. Thanks for spotting the missing hash sign. If I delay the autojoin I can part the banned channel(s) before the status is updated and thus close the window.
Thanks a lot for your help

If anyone know a better way of doing it feel free to let me know.