I was wondering, you don't have any addon loaded to MSN - winamp and so on? i remember that winamp can show to mirc what song you playing, and that this addon was able to send a /command to mirc. cos i can't think of anything else then that it must be something outside your mirc that sends the command to the server. (if you are 100% sure you have a clean mirc installed)

if ($me != tired) { return } | else { echo -a Get a pot of coffee now $+($me,.) }