Comment 3 for bug 1121193

Try modifying this file:
--- a/usr/share/polkit-1/actions/org.freedesktop.consolekit.policy
+++ b/usr/share/polkit-1/actions/org.freedesktop.consolekit.policy
@@ -23,7 +23,7 @@ Policy definitions for ConsoleKit
     <message>System policy prevents stopping the system when other users are logged in</message>
     <defaults>
       <allow_inactive>no</allow_inactive>
- <allow_active>auth_admin_keep</allow_active>
+ <allow_active>yes</allow_active>
     </defaults>
   </action>

@@ -41,7 +41,7 @@ Policy definitions for ConsoleKit
     <message>System policy prevents restarting the system when other users are logged in</message>
     <defaults>
       <allow_inactive>no</allow_inactive>
- <allow_active>auth_admin_keep</allow_active>
+ <allow_active>yes</allow_active>
     </defaults>
   </action>