Comment 113 for bug 568611

@JeanAustinR - In reference to comment #110: No, the brightness issues have not yet been fixed in the official Ubuntu kernels.

@Bogdan - The inverted behavior is very curious indeed. To help further diagnose the cause, please run these commands in a terminal window:
  $ cd /sys/class/backlight/intel_backlight
  $ cat max_brightness
Please report the "max brightness" value that gets printed out here. For example, mine yields the value 4882.

Now try changing the brightness manually to various fractions of your max value, for example with my max of 4882, I do:
  $ echo 1000 | sudo tee brightness # this should be very dark
  $ echo 2400 | sudo tee brightness # should be about half brightness
  $ echo 4882 | sudo tee brightness # should be maximum brightness
(don't set the brightness to 0, or else your screen will likely go totally dark).

When you change the brightness manually this way, does the actual screen brightness behave as expected or is the behavior "inverted"?