ajaypal.com

I solved it like this:
+++++++++++++++++++++++++++++++++++++
sudo gedit /etc/acpi/video_brightnessup.sh
Replace everything in this file with:

#!/bin/bash

CURRENT=$(grep "current:" /proc/acpi/video/OVGA/DD03/brightness |awk '{print $2}')

case "$CURRENT" in

100)
echo -n 100 > /proc/acpi/video/OVGA/DD03/brightness;
;;
90)
echo -n 100 > /proc/acpi/video/OVGA/DD03/brightness;
;;
80)
echo -n 90 > /proc/acpi/video/OVGA/DD03/brightness;
;;
70)
echo -n 80 > /proc/acpi/video/OVGA/DD03/brightness;
;;
60)
echo -n 70 > /proc/acpi/video/OVGA/DD03/brightness;
;;
50)
echo -n 60 > /proc/acpi/video/OVGA/DD03/brightness;
;;
40)
echo -n 50 > /proc/acpi/video/OVGA/DD03/brightness;
;;
30)
echo -n 40 > /proc/acpi/video/OVGA/DD03/brightness;
;;
*)
echo -n 100 > /proc/acpi/video/OVGA/DD03/brightness ;
;;
esac

--------------END of VIDEO-BRIGHTNESS_UP---------

Now do the brightness_down file:

--------------BEGIN BRIGHTNESS_DOWN------------
sudo gedit /etc/acpi/video_brightnessdown.sh
Replace everything in this file with:

#!/bin/bash

CURRENT=$(grep "current:" /proc/acpi/video/OVGA/DD03/brightness |awk '{print $2}')

case "$CURRENT" in

30)
echo -n 30 > /proc/acpi/video/OVGA/DD03/brightness;
;;
40)
echo -n 30 > /proc/acpi/video/OVGA/DD03/brightness;
;;
50)
echo -n 40 > /proc/acpi/video/OVGA/DD03/brightness;
;;
60)
echo -n 50 > /proc/acpi/video/OVGA/DD03/brightness;
;;
70)
echo -n 60 > /proc/acpi/video/OVGA/DD03/brightness;
;;
80)
echo -n 70 > /proc/acpi/video/OVGA/DD03/brightness;
;;
90)
echo -n 80 > /proc/acpi/video/OVGA/DD03/brightness;
;;
100)
echo -n 90 > /proc/acpi/video/OVGA/DD03/brightness;
;;
*)
echo -n 60 > /proc/acpi/video/OVGA/DD03/brightness ;
;;
esac

----------END VIDEO=BRIGHTNESS_DOWN------------
Save both files.