As you get back to the login screen this is most likely a error in X assigning it as such. See https://wiki.ubuntu.com/Bugs/FindRightPackage for hints on how to find the correct package.
To debug this issue we need some more info, can you run the command 'apport-collect 562419' from a terminal. It will collect and attach the information we need here. ** Package changed: ubuntu => xorg-server (Ubuntu) ** Changed in: xorg-server (Ubuntu) Status: New => Incomplete -- Opera 10.10 crashes complete Xsession https://bugs.launchpad.net/bugs/562419 You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg-server in ubuntu. _______________________________________________ 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