After upgrading Ubuntu Netbook Remix, the shutdown applet may be absent from the top panel. As a workaround, move the current applets to make some available space on the panel, then right-click in the freed space to add the "Indicator Applet Session" applet manually. See Bug:461115 for detailed instructions.
Documented at <https:/ /wiki.ubuntu. com/KarmicKoala /ReleaseNotes# Ubuntu% 20Netbook% 20Remix% 20missing% 20shutdown% 20applet% 20after% 20upgrade>:
After upgrading Ubuntu Netbook Remix, the shutdown applet may be absent from the top panel. As a workaround, move the current applets to make some available space on the panel, then right-click in the freed space to add the "Indicator Applet Session" applet manually. See Bug:461115 for detailed instructions.