PolicyKit error when installing software via software-center

Might be the same problem experienced in this bug in 11.10:
https://bugs.launchpad.net/ubuntu/+source/software-center/+bug/785117
After upgrading from 13.10 to 14.04 LTS installing software via the software center fails due to policykit not authenticating the installation.
(Authentication Error: Software can't be installed or removed because the authentication service is not available. (org.freedesktop.PolicyKit.Error.Failed: ('system-bus-name', {'name': ':1.1084'}): org.debian.apt.install-or-remove-packages)
I suppose that due to the upgrade, policykit was removed from the startup items. After putting it back there, everything works as intended. Unlike in the other bug report, this time (due to the work on the other bug) there is correct Error handling in place. But again, there should be a fallback state like gksu if policykit is not running, and the upgrader for 14.04 might need patching so he does not remove policykit from the startup items (Although I am not sure if I accidentally removed or killed it somehow, but the corellation with the upgrade suggests it was the upgrader).

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: software-center 13.10-0ubuntu4
ProcVersionSignature: Ubuntu 3.13.0-24.46-generic 3.13.9
Uname: Linux 3.13.0-24-generic x86_64
ApportVersion: 2.14.1-0ubuntu3
Architecture: amd64
Date: Sat Apr 19 14:35:59 2014
InstallationDate: Installed on 2014-01-14 (94 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
PackageArchitecture: all
SourcePackage: software-center
UpgradeStatus: Upgraded to trusty on 2014-04-18 (0 days ago)