Apparently this problem is already known: http://ubuntuforums.org/showthread.php?t=1613132
Since I'm able to boot to a shell, what I just did was to add nomodeset to /etc/default/grub and run update-grub, as described on the ubuntuforums page above. So now the altered line in /etc/default/grub looks like GRUB_CMDLINE_LINUX_DEFAULT="quiet splash nomodeset" -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-nouveau in Ubuntu. https://bugs.launchpad.net/bugs/946116 Title: lightdm fails to bring up X display automatically after boot To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-nouveau/+bug/946116/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp
