This is what I did to get the backlight brightness buttons working:
change /etc/acpi/thinkpad-brightness-down.sh to just: /usr/bin/xbacklight -8
and /etc/acpi/thinkpad-brightness-.sh to just: /usr/bin/xbacklight +7
and comment the rest out.
(If the 2 numbers are relatively prime you can set the brightness to the nearest 1 unit by "twiddling" up and down.)
Useful tool for keeping track of changes to config files: apt-get install etckeeper. On a laptop, put resolv.conf in .git/info/exclude -- since dhcp overwrites it.
-- Don Marti 2008-04-05 01:40 UTC