Did you check the status window in irc? It is possible that the nickname your trying to change to (ie Jim) is already registered to another person, and if this is the case, the IRC server will not let you change to that nickname, its NOT an mIRC problem. Also, what network was this on, that will help determine if the nickname you tried to use is already registered to someone else.
Thanks
I changed my nick name to Jim|Away before the weekend, and went to Change it back to my real name Brother_Jim, but to answer your question no that name was not in use nor anyone else has it register, the network is irc.flumpirc.net and i am also a service admin on that network, this has happen the 3rd time and as i said once i deleted mirc and reinstalled it the nick change command works for a bit and then stops.
