Thanks for your bug report. The mode display routine in mIRC, which creates the mode you see in the channel titlebar, checks to make sure that only alphabetic characters are included. The routine has worked this way for about a decade, so it is difficult to say why it performs this check. It may be that some ircds were passing number parameters as part of the mode itself, so mIRC was stripping them out. As far as I can tell, the current behaviour does not affect the way mIRC handles modes, only their display in the channel titlebar. Unless someone can think of a reason not to, I will remove the alphabetic check for the next version.