Same problem here: after I upgraded gnome-panel from 2.24 to 2.26, the shutdown option disappeared from the menu. However, when you hit Ctrl-Alt-Del, the shutdown dialog appears and the buttons on it work as they should.
-- Dmitry Borodaenko -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]
