Alright, I'm pretty computer savvy but this issue has me scratching my head! I have an Apple TV and lots of movies/tv shows that are in either mp4 or m4v format. Those formats are Apple TV compatible and work great streaming from my MacBook Pro to my Apple TV. The problem that has me scratching my head is I have an external monitor that I hook my MacBook Pro up to and then I close the lid of the MacBook Pro. What I have found is once I close the lid of my MacBook Pro and use my external monitor my Apple TV no longer can read my files on my computer to stream. Apple TV can still see all my Movies/TV shows but when I click play, Apple TV says, the file is in the incorrect format and can not play. I tested to make sure it was indeed the close lid. It was since once I opened my MacBook Pro lid I was able to play files on my Apple TV again. For some reason closing the lid won't allow me to connect to Apple TV. Has anyone had this issue or know the fix? The only thing I can think could be causing this is Apple TV thinks my computer is in sleep mode when the lid is closed and therefore can't connect to Apple TV. Any help would be greatly appreciated. Thanks