Backlight doesn't persist at all

Binary package hint: gnome-power-manager

Description: Ubuntu hardy (development branch)
Release: 8.04

gnome-power-manager:
  Installed: 2.22.1-1ubuntu2
  Candidate: 2.22.1-1ubuntu2
  Version table:
 *** 2.22.1-1ubuntu2 0
        500 http://se.archive.ubuntu.com hardy/main Packages
        100 /var/lib/dpkg/status

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The backlight preferences adjusted with Fn + <keys> does not persist after a reboot or from suspending the computer. Instead i set the backlight with "echo 8 > /proc/acpi/video/EGFX/LCD0/brightness" in rc.local and with a pm hook to achieve the same effect.
Also, running on battery power makes it even worse, since it doesn't even stay at what level i adjust to, but constantly dims (after the timeout), and stays that way until i turn it up manually (with the Fn keys) again (and again, and again).
I will gladly supply any other info you request from me. Thanks.