I was hoping that 10.7.3 would finally fix it, but alas. Since the last OS X update I've had issues using my 11" 2011 MacBook Air with an external monitor. Primarily they revolve around clamshell mode and using only an external display instead of display mirroring or extension. Prior to 10.7.2 if you closed the lid with an external display connected the screen would flash blue and the computer would output solely to the external display. You could also wake the machine from sleep if it was closed but connected to another monitor, and in the same case only the external display would output. Since the update (and its accompanying GPU driver update) the only way I can solely use the external display is if I reboot or power on the machine with the lid closed. This is obviously a pain, especially if I'm just waking from sleep, and I'd love to figure out a way to restore previous functionality. I have a late 2010 15" MacBook Pro and I've confirmed that with its ATI card this problem does not exist (I can get into clamshell mode by closing the screen or waking from sleep fine) but that's likely down to the different graphics card. Any solutions? I've googled and found a variety of similar issues going back way before the September update but nothing that seems spot on.