package lightdm 1.2.3-0ubuntu2.3 failed to install/upgrade: subprocess installed post-removal script returned error exit status 1

[nemtna]

After using GDM (since LightDM loop,) I decided to uninstal and install LightDM. This allowed me to login (albeit paintakenly slow, because the screen flashed about 4 or 5 times before completely rendering the desktop - i.e., all the icons and Unity sidebar showed.) However, although it showed the desktop, somehow, I had to login again. It was as if I was logged in with a phantom user.

ProblemType: Package
DistroRelease: Ubuntu 12.04
Package: lightdm 1.2.3-0ubuntu2.3
ProcVersionSignature: Ubuntu 3.2.0-52.78-generic 3.2.48
Uname: Linux 3.2.0-52-generic i686
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu17.4
AptOrdering: lightdm: Purge
Architecture: i386
Date: Mon Aug 26 17:05:59 2013
DuplicateSignature: package:lightdm:1.2.3-0ubuntu2.3:subprocess installed post-removal script returned error exit status 1
ErrorMessage: subprocess installed post-removal script returned error exit status 1
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release i386 (20110427.1)
MarkForUpload: True
SourcePackage: lightdm
Title: package lightdm 1.2.3-0ubuntu2.3 failed to install/upgrade: subprocess installed post-removal script returned error exit status 1
UpgradeStatus: Upgraded to precise on 2012-04-29 (484 days ago)