I'm reopening this because I'm in a similar situation as Kevin. My friend's computer does not come up to a greeter login after updating it from natty to oneiric. I put the following into root's crontab for now to take of the situation.
@reboot sleep 22; service lightdm stop;service lightdm start ** Changed in: lightdm (Ubuntu) Status: Fix Released => Confirmed -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to lightdm in Ubuntu. https://bugs.launchpad.net/bugs/816646 Title: no log in screen due to lightdm greeter not being installed Status in “lightdm” package in Ubuntu: Confirmed Bug description: just updated to lightdm 0.9 but now login issn't working anymore... I had to go back to gdm to log in again.... ProblemType: Bug DistroRelease: Ubuntu 11.10 Package: lightdm 0.9.2-0ubuntu1 ProcVersionSignature: Ubuntu 3.0.0-7.8-generic 3.0.0 Uname: Linux 3.0.0-7-generic x86_64 Architecture: amd64 Date: Tue Jul 26 23:06:05 2011 InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1) SourcePackage: lightdm UpgradeStatus: Upgraded to oneiric on 2011-07-22 (3 days ago) mtime.conffile..etc.lightdm.lightdm.conf: 2011-07-26T22:48:10.562849 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lightdm/+bug/816646/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp