Samsung P560 brightness control via fn keys does not work

[gabriel]

Hello,

I am running Ubuntu Lucid on my Samsung P560 notebook

• - Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller
  - Linux 2.6.32-25-generic #46~ppa1~loms~lucid-Ubuntu SMP Fri Oct 22 23:33:19 UTC 2010 i686 GNU/Linux

The modules easy_slow_down_manager and samsung_backlight are successfully loaded.
If I try to change the brightness via fn keys + "up/down" gnome desktop shows the changes,
but there is no effect to the real brightness. After analysing the /proc and /sys file system
I have found following entries

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/proc/acpi/video/GFX0/DD04/brightness
/sys/devices/virtual/backlight/acpi_video0/brightness

which represent the settings/changes by the fn keys. However, there is another entry
(managed by the samsung_backlight module)

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 /sys/devices/virtual/backlight/samsung/brightness

which is not affected by the fn keys. But I can successfully change the brightness of
the backlight on the command line:

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bash>  echo 2 > /sys/devices/virtual/backlight/samsung/brightness

Can anybody help me to solve the problem?

Kind regards
Andreas