I have a rev. A MBA and it does two odd things. If I set the display to full brightness, then power down and back up, the display doesn't return to full brightness. I have to go into the display preferences pane and move the slider a fraction of an inch to return to full brightness. The "adjust brightness for ambient light" and "reduce brightness on this power source" are disabled, so that isn't it. Also, the MBA forgets the brightness setting for the keyboard when it is powered off and then on again. As best I can determine the keyboard brightness is set to a random level at power up. I've used MacBook Pros for years, so I don't think it's anything I'm doing. Any ideas abou this would be welcome.