i think there should a be a move file option in the script editor, many a time i move a script to a different directory and then $scriptdir still returns the directory it was in when you loaded it.
This is cos the scripts are loaded into memory on mIRC startup (if you've set them to auto-load on mIRC execution) and so any changes you make to the scripts are only stored in memory until you save. You best bet is to unload, move and then reload the scripts
