Well common sense dictates that one associates the problem with the common cause, that being mIRC's adverse response to the case change on mode change. If the problem is happening on two entirely different brands of IRCd then Khaled should build some resistance into mIRC to prevent the case change happening. Lets not forget here that +o is an op/deop mode, not a case change mode, that said you barely had a valid arguement with +yu in the case of CR. In the case of whatever other IRCd affects mIRC this way, you have absolutely no valid argument at all.

While I am on the subject, I tried this issue in X Chat, Klient, Bersirc and kVirc. I even telnetted for what it was worth (even though there's no nicklist in DOS I was still able to see the full raw event). No other chat client that I know of is affected by this - only mIRC. The bug is therefore in mIRC.