In Zwei in Experimental MIT-Specific 18.0, Experimental System 93.5, Experimental ZMail 49.1, microcode 226, gc@2, on Lisp Machine Five: When I do M-X Midas and then M-X Update Mode Line in an empty buffer (maybe even in a full one) I get -*- Mode: LISP -*-, even though the mode was successfully set to Midas.