JK_STL,
unfortunatly it seems that your problem is not the the same as mine. It might be that your Nickname is not registered and you are trying to use a nickname from another person who is registered at this server.
I guess you should choose a nick first individual for yourself and once you are on the server, you register your name with:
/msg nickserv register your_password_of_your_own_choice your_email
After that the server will answer that u are registered. Keep your password in mind and this line is to enter into the perform of mIRC:
/msg nickserv identify your password
If it is not the problem... pls feel free to write back
