Refer to bug 257827 and can see this is a long-time issue (and comment #89 even mentions the issue is non-existent in Fedora).
** Changed in: gnome-settings-daemon (Ubuntu) Assignee: (unassigned) => Ayan George (ayan) -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-settings-daemon in Ubuntu. https://bugs.launchpad.net/bugs/887853 Title: 2 levels of brightness change on single key press Status in “gnome-settings-daemon” package in Ubuntu: Confirmed Bug description: On my Asus laptop K53U, /usr/lib/gnome-settings-daemon/gsd-backlight- helper adjusts /sys/class/backlight/acpi_video0 when receiving KEY_BRIGHTNESS-UP/-DOWN while the BIOS in fact adjusts the brightness itself on the key pressed too. This causes two levels of backlight brightness change on one key press. --- ApportVersion: 1.23-0ubuntu3 Architecture: amd64 DistroRelease: Ubuntu 11.10 InstallationMedia: Ubuntu 11.10 "Oneiric" - Build amd64 LIVE Binary 20111028-04:06 Package: gnome-settings-daemon 3.2.1-0ubuntu3 PackageArchitecture: amd64 ProcEnviron: LANGUAGE=en_US: PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4 Tags: oneiric running-unity Uname: Linux 3.0.0-12-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-settings-daemon/+bug/887853/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp