So I installed the proprietary ATI drivers for my laptop and every time, before i log in, the screen goes to a 100% brightness, totally annoying, my FN keys works well, and the kde brightness properties works fine as far as i know.
So i googled and found i could change /sys/class/backlight/acpi_video0/max_brightness the problem is that every time i tried i got a permission error
i tried login as root same error don't know what ive done wrong.

the problem is before i log in so i suppose the video driver mess up my settings when it loads maybe there is a better solution for this...
Ill appreciate your responses.

mobility radeon HD 4250
Kubuntu 11.04
PD sorry if my english is bad