Comment 0 for bug 1783637

After upgrading to 18.04, on xfce4 with Display Power Management (xfce4-power-manager) enabled, and any of the three sliders set to non-zero, then when the time limit is hit after inactivity the screen goes black with a cursor flashing. Two Xorg logs are created when this happens (see attached). Ctrl-Alt-F# will switch to other ttys at this point, but only briefly before switching back to the one that is black with a single flashing cursor.

(I would expect things to happen as in 17.10, namely that the displays blank/switch off as selected, and then when further input is given they unblank/switch on.)

lsb_release -rd:
Description: Ubuntu 18.04 LTS
Release: 18.04

apt-cache policy xfce4-power-manager:
xfce4-power-manager:
  Installed: 1.6.1-0ubuntu1
  Candidate: 1.6.1-0ubuntu1
  Version table:
 *** 1.6.1-0ubuntu1 500
        500 http://gb.archive.ubuntu.com/ubuntu bionic/universe amd64 Packages
        100 /var/lib/dpkg/status

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: xfce4-power-manager 1.6.1-0ubuntu1
ProcVersionSignature: Ubuntu 4.15.0-29.31-generic 4.15.18
Uname: Linux 4.15.0-29-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.20.9-0ubuntu7.2
Architecture: amd64
CurrentDesktop: XFCE
Date: Wed Jul 25 21:10:33 2018
InstallationDate: Installed on 2017-05-13 (438 days ago)
InstallationMedia: Xubuntu 17.04 "Zesty Zapus" - Release amd64 (20170412)
SourcePackage: xfce4-power-manager
UpgradeStatus: Upgraded to bionic on 2018-07-16 (9 days ago)