I was seamlessly able to use my cinema display when the lid was closed before. Now when the lid is closed and it wakes up, it goes back to sleep. After pressing F7 twice I get my MacBook Pro display back up but at full brightness and can't bring it back down. I tried the PRAM reset and the one where you remove all power, repaired the disk and repair all the permissions. Sometimes it will work but after a reboot it's not working anymore. Help.