After resume, a black screen, flashing when moving mouse

[David Henningsson]

After suspend/resume, I was left with an almost black screen - the only visible thing was a top bar saying "Light Display Manager" and a keylock.
When moving the mouse, the screen flashes (showing Ubuntu's background image and a mouse arrow) but quickly turns black again.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: lightdm 1.0.0-0ubuntu2
ProcVersionSignature: Ubuntu 3.0.0-12.19-generic 3.0.4
Uname: Linux 3.0.0-12-generic x86_64
ApportVersion: 1.23-0ubuntu2
Architecture: amd64
Date: Thu Sep 29 10:00:16 2011
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Alpha amd64 (20110802.1)
ProcEnviron:
 LANG=sv_SE.UTF-8
 SHELL=/bin/bash
SourcePackage: lightdm
UpgradeStatus: No upgrade log present (probably fresh install)

[David Henningsson (diwic)]

When this happened, I switched to a VT, and collected apport information. I'm attaching that here. After that, I rebooted to be able to file the bug.

[Donald (78luphr0rnk2nuqimstywepozxn9kl19tqh0tx66b5dki1xxsh5mkz9gl21a5rlwfnr8jn6ln0m3jxne2k9x1ohg85w3jabxlrqbgszpjpwcmvkbcvq9spp6z3w5j1m33k06tlsf-c04cs2xj0-a811i2i3ytqlsztthjth0svbccw8inm65tmkqp9sarr553jq53in4xm1m8wn3o4rlwaer06ogwvqwv9mrqoku2x334n7di44o65qze67n1wneepmidnuwnde1rqcbpgdf70gtqq2)]

I'm on Ubuntu 12.04 LTS. My uname:

Linux silent 3.6.10 #1 SMP Mon Jan 7 23:10:14 CET 2013 x86_64 x86_64 x86_64 GNU/Linux

The problem started occurring once I didn't leave my log-in on all the time but had additional accounts for other people where we now log off or switch users using the Unity desktop. The problem particularly seems occurring when a user logs off and the lightdm greeter should be displayed, while one or more other user sessions are running in the background.

It's hard to believe that this problem has been confirmed, yet ignored for more than two years...

[Donald (78luphr0rnk2nuqimstywepozxn9kl19tqh0tx66b5dki1xxsh5mkz9gl21a5rlwfnr8jn6ln0m3jxne2k9x1ohg85w3jabxlrqbgszpjpwcmvkbcvq9spp6z3w5j1m33k06tlsf-c04cs2xj0-a811i2i3ytqlsztthjth0svbccw8inm65tmkqp9sarr553jq53in4xm1m8wn3o4rlwaer06ogwvqwv9mrqoku2x334n7di44o65qze67n1wneepmidnuwnde1rqcbpgdf70gtqq2)]

Here the output of
$ apt-cache policy lightdm
lightdm:
  Installed: 1.2.3-0ubuntu2.3
  Candidate: 1.2.3-0ubuntu2.3
  Version table:
 *** 1.2.3-0ubuntu2.3 0
        500 http://de.archive.ubuntu.com/ubuntu/ precise-updates/main amd64 Packages
        100 /var/lib/dpkg/status
     1.2.1-0ubuntu1 0
        500 http://de.archive.ubuntu.com/ubuntu/ precise/main amd64 Packages