ed automatically. Ensure that it does :
cat /var/log/Xorg.0.log | grep -i aiglx
which should say (==) AIGLX enabled (with a bunch of errors after that). ... en type in:\\
gconf-editor &\\
go through the logical progression (apps/compiz/general/allscreens/o
t menu > Control Center > System administration > Login manager. Press the "Administrate" button if necessary, then go to the Shutdown tab and check "Display suspend button in logout window".