I found that apparently it had nothing to do with lightdm. It was a conflict between xfce-power-manager and systemd. This solution worked for me, suspend and resume now work:
http://ubuntuforums.org/showthread.php?t=2184892 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1301549 Title: Black screen after logging in after resume in Xubuntu 14.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lightdm/+bug/1301549/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
