When I installed XBMC in Raspbian I noticed that the shutdown menu only had the “Exit” button, which returned me to the ussual terminal login screen. I want my parents to use this media center so I have to make it as simple as possible.
After some time searching on the net I found the solution. You have to become root (using su, note that if you haven’t yet changed roots password you can do it by running sudo passwd) and create a file named /var/lib/polkit-1/localauthority/50-local.d/xbmc.pkla with those options (in my case I had to change the xbmc user to pi because thats the one that runs XBMC):
[Actions for xbmc user] Identity=unix-user:xbmc Action=org.freedesktop.upower.*;org.freedesktop.consolekit.system.* ResultAny=yes ResultInactive=yes ResultActive=yes
If you want to change or remove some of the menu options in the shutdown window just edit the /usr/share/xbmc/addons/skin.confluence/720p/DialogButtonMenu.xml file. There you can change the <visible> option to “no” if you want to hide a button for example.
Ref: http://www.raspberrypi.org/phpBB3/viewtopic.php?p=127003
http://wiki.xbmc.org/index.php?title=HOW-TO:Suspend_and_wake_in_Ubuntu