light-locker blanking settings not taking effect

[Bruce Merry]

I've used light-locker settings to set a blank time of 4 minutes and a display suspend time of 6 minutes. However, when I power up the machine and log in, these settings are not in effect, and 'xset q' reports the following (unrelated output cut):

Screen Saver:
  prefer blanking: yes allow exposures: yes
  timeout: 0 cycle: 0
...
DPMS (Energy Star):
  Standby: 7200 Suspend: 7200 Off: 14400
  DPMS is Disabled

I can see that ~/.config/autostart/screensaver-settings.desktop has been written correctly. I've also replaced xset with a wrapper that logs calls, from which I can see that the autostart command is being run, and that immediately afterwards xset q reports the expected values. So something is presumably overriding the settings shortly afterwards, but it is not calling the xset binary (presumably it pokes the X server directly).

I don't know if it is related to power management settings. This is on a laptop plugged into the mains and with no battery present. As far as I remember I haven't configured any power management settings in XFCE, but I'm not 100% sure. laptop-mode-tools is installed but I haven't touched the configuration for it.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: light-locker-settings 1.0.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-16.36-generic 3.13.5
Uname: Linux 3.13.0-16-generic x86_64
ApportVersion: 2.13.3-0ubuntu1
Architecture: amd64
CurrentDesktop: XFCE
Date: Tue Mar 11 21:08:14 2014
InstallationDate: Installed on 2014-03-10 (1 days ago)
InstallationMedia: Xubuntu 14.04 LTS "Trusty Tahr" - Alpha amd64 (20140225)
PackageArchitecture: all
SourcePackage: light-locker-settings
UpgradeStatus: No upgrade log present (probably fresh install)

[Bruce Merry (bmerry)]

xscreensaver seems to be partially to blame. After uninstalling it, logging out and logging in, xset q reports

Screen Saver:
  prefer blanking: yes allow exposures: yes
  timeout: 240 cycle: 600
...
DPMS (Energy Star):
  Standby: 600 Suspend: 0 Off: 900
  DPMS is Enabled
  Monitor is On

So the 4 minute blanking timeout is now respected, but the DPMS timeout has been set to 10 minutes instead of the requested 6 (and the DPMS off time has been set to 15 minutes, instead of 0 as in the xset command written by light-locker-settings).