I don’t really know how they might be related, but for the brightness control in KDE4.3 (openSUSE 11.2, HP 6730s laptop with Intel GM45) to work, I need to boot with avahi-daemon enabled in chkconfig at boot time. 
Running avahi-daemon afterwards, and restart xdm does not work.
Anyway, what has avahi-demon to do with the brightness control???