No explanation when shutdown/restart is denied due to other logged user(s)

[netvor]

If you have a user logged in and you try to shutdown or restart as another user or from the login screen, you are denied the restart but there is no proper feedback for that. In other words, you don't receive any error message or explanation about the denial--simply nothing happens.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: gnome-session 3.2.1-0ubuntu8
ProcVersionSignature: Ubuntu 3.2.0-30.48-generic 3.2.27
Uname: Linux 3.2.0-30-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu12
Architecture: amd64
Date: Sun Sep 9 23:30:26 2012
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
PackageArchitecture: all
SourcePackage: gnome-session
UpgradeStatus: Upgraded to precise on 2012-09-09 (0 days ago)