Shutdown button in "User panel" logs out user instead of halting PC

[Giulio De Pasquale]

When pressing the "Shutdown.." button in the user panel, Unity logs out the user instead of shutting down the PC.
In the login screen, the brightness is set to the lowest possible. Happens every time I try to halt my PC.

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: unity 7.3.1+14.10.20141016-0ubuntu1
ProcVersionSignature: Ubuntu 3.16.0-25.33-generic 3.16.7
Uname: Linux 3.16.0-25-generic x86_64
ApportVersion: 2.14.7-0ubuntu8
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CurrentDesktop: Unity
Date: Mon Dec 8 17:27:17 2014
EcryptfsInUse: Yes
InstallationDate: Installed on 2014-11-20 (17 days ago)
InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)