After update, signing into lightdm just returns to unity-greeter

[Chris Wayne]

After updating on September 26, restarting my system had some interesting issues. First, after the update and subsequent reboot, it came up and said it would start in low graphics mode. If you selected ok, it would just reload that dialog, never even loading low graphics mode. Upon further inspection, ubuntu-desktop and gnome-session were somehow uninstalled. Installing those and launching lightdm, if I enter my password, it just brings me back to the unity-greeter

HW:
Lenovo t420s
Intel graphics

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: lightdm 1.3.3-0ubuntu4
ProcVersionSignature: Ubuntu 3.5.0-15.23-generic 3.5.4
Uname: Linux 3.5.0-15-generic x86_64
ApportVersion: 2.5.2-0ubuntu4
Architecture: amd64
Date: Wed Sep 26 22:41:07 2012
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
ProcEnviron:
 LANGUAGE=en_US:en
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: lightdm
UpgradeStatus: Upgraded to quantal on 2012-09-07 (19 days ago)

[Robert Ancell (robert-ancell)]

Closing assumed fixed.