A solution for this problem that works for me (ubuntu 10.10, 2.6.35-24 kernel) is described here http://ubuntuforums.org/showthread.php?t=1612560
In a nutshell, add the boot option "acpi_osi=" to grub, by executing $ gksudo gedit /etc/default/grub (which calls an editor) to replace in the file /etc/default/grub the line GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" with GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=" Then execute $ sudo update-grub and reboot. Backlight-changing should now work seamlessly. Axel -- To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20110115.130129.315817196905527759.a...@rossberg.net