This is due to the design of mirc.ini, where nick settings are in the same section with other type of windows. For example, go into options/irc/logging, and inside "automatic log and reload", and check both boxes for "chat" and the box for "status". After doing some commands to put some extra chatter into the status window, this command will open a query window to a nick named 'status' containing the contents from your status window:
/query status
then uncheck those options if you don't want them anymore
