After some digging I had to realize, that the thinkpad_acpi module is functioning well, the error is in XFCE-s display brightness setter.
This is a duplicate of: https://bugzilla.xfce.org/show_bug.cgi?id=7541 http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=627336 Workaround solution: http://www.n0nb.us/blog/2012/02/restoring-screen-brightness-step-size-on-xfce4/ -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected] Archive: http://lists.debian.org/[email protected]

