Used my Macbook display for most of the day-- yesterday and again today [only 10:00 a.m. here now-- however I have been up since 5:00 a.m.].

Wanted to provide a little more information as related to this experience.

I tent my work area a lot-- especially when I am developing software. Back in October [2011] when I first started having problems with the display, I was working day and night in a tented environment. Meaning very little light other than the display itself. I was also using a newer release of Firefox which seemed to cause my system to run hot-- and lock up often. I often rebooted or the system crashed in this tented environment.

Another issue-- as reported in the post I did at the time [October 2011], my battery had expanded and was causing problems with the track pad. Battery compartment directly under the track pad on my model.

I believe the constant rebooting of the system in the tented [darkened] environment-- caused a re-calibration of the algorithm used to adjust the display brightness based on the Ambient Light Sensor. My Macbook is older and does not allow this sensor to be disabled in the System Preferences.. though I did research extensively a solution with a plist. I believe the plist associated with this problem is the com.apple.BezelSystems.plist.

I also believe my sensor is co-located with the speakers on the back of the base of the notebook.

Given all of this, last night in an effort to re-calibrate the sensor-- I turned on every light in the area- and rebooted the system several times.. [think more than 10..] changing the System Preferences brightness levels each time. I did not set it to maximum brightness. This seems to have done the trick.

So, how will I work in a tented area in the future? With a lamp in my tent..