Backported from X.org's Xserver:

    commit c1d901d723c3bee523736eacc15b44a7dff484fe
    Author: Richard Hughes <richard@hughsie.com>
    Date:   Fri Aug 14 11:44:35 2009 +0100

        Don't reset the lastDeviceEventTime when doing DPMS actions

        When we change the DPMS mode, don't play games with the last event time as
        this breaks applications using IDLETIME to turn the backlight off after a
        preset time.

        This patch fixes gnome-power-manager and xfce-power-manager
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Backport-to-NX-by: Mike Gabriel <mike.gabriel@das-netzwerkteam.de>