I can't help (N800 here), but with my N800 desktop files are required in certain places to get a widget to show up. In your case, to get something to show up there, a desktop file will have to have been placed in /usr/share/applications/hildon-status-menu. What's the result of running ls /usr/share/applications/hildon-status-menu? Maybe someone can tell you if a desktop file is there that shouldn't be there