Something that's been bugging me for a while now, but why when I switch MBP the brightness has gone down to 1 square, the first setting. It's no big deal but I'm curious as to why it's doing this now after nearly 5 years. 'Slightly dim display when not on power source' was unticked years ago, so not relevant to that, but even then it never went that low. It's typically set at the 5th square, but after restart it opens on 1. Anyone have any idea. I've had the MBP since early 2011, 10.6.8. SL, and it's only just started doing this in the last couple of months.