I've attempted to change the Backlight Brightness, by both the keyboard setting and directly in the screen settings. Both show that I've changed the brightness down to minimum neither actually changed the brightness level.
did you enable the backlightbrightness to changable in xorg.conf?
remember, you need administrative properties for that, so open a terminal and do:
sudo gedit /etc/x11/xorg.conf
then please put this
into the file /etc/X11/xorg.conf file ..
like shown here:
Section "Device" .. .. .. Option "RegistryDwords" "EnableBrightnessControl=1" EndSection
that should solve it