Which video driver are you using? If you're using Intel graphics I'll mark this as a duplicate under bug #966744.
** Changed in: lightdm (Ubuntu) Status: New => Incomplete -- 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/1034075 Title: desktop fails to resume after suspend Status in “lightdm” package in Ubuntu: Incomplete Bug description: Roughly half the time, on resuming from suspend I see only a black screen with a cursor, forcing me to restart lightdm. ProblemType: Bug DistroRelease: Ubuntu 12.04 Package: lightdm 1.2.1-0ubuntu1.1 ProcVersionSignature: Ubuntu 3.2.0-27.43-generic-pae 3.2.21 Uname: Linux 3.2.0-27-generic-pae i686 ApportVersion: 2.0.1-0ubuntu11 Architecture: i386 CheckboxSubmission: 4dd233a4bc5d54d6155d703ad96994b1 CheckboxSystem: 5f4ecd6d71eb8a96079c2379174a82c5 Date: Tue Aug 7 10:20:51 2012 InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release i386 (20120423.2) ProcEnviron: PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: lightdm UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lightdm/+bug/1034075/+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