(Ubuntu 12.04, newly installed with package 'python-awn-extras' v. 0.4.1~bzr1507-0ubuntu7)
In yama.py (typically located in /usr/share/avant-window-navigator/applets/yama/), some handler information (presumably outdated) was left on both logout_item.connect and shutdown_item.connect.
logout_item = self.append_menu_item(menu, _("Log Out %s...") % user_name, "system-log-out", _("Log out %s of this session to log in as a different user") % user_name)
logout_item.connect("activate", lambda w: sm_iface.Logout(0, reply_handler=dummy_cb, error_handler=error_cb))
self.session_items.append(logout_item)
shutdown_item = self.append_menu_item(menu, _("Shut Down..."), "system-shutdown", _("Shut down the system"))
shutdown_item.connect("activate", lambda w: sm_iface.Shutdown(reply_handler=dummy_cb, error_handler=error_cb))
self.session_items.append(shutdown_item)
The dummy_cb got in the way and these two items never actually worked.
I was able to fix this by removing references to the reply_handler and error_handler:
logout_item = self.append_menu_item(menu, _("Log Out %s...") % user_name, "system-log-out", _("Log out %s of this session to log in as a different user") % user_name)
logout_item.connect("activate", lambda w: sm_iface.Logout(0))
self.session_items.append(logout_item)
shutdown_item = self.append_menu_item(menu, _("Shut Down..."), "system-shutdown", _("Shut down the system"))
shutdown_item.connect("activate", lambda w: sm_iface.Shutdown())
self.session_items.append(shutdown_item)
