I have a new (03/11) Macbook Pro 17" connected to a Samsung 40" display via mini-displayport to HDMI. I also have a AppleTV 1 connected to HDMI. My problem is related to switching between the two computers. When I switch from the Macbook to the atv all is fine. However, when I switch back to the Macbook, the external tells me no signal detected and I'm forced to open the lid and jigger the mouse around until the external display cycles on. I've tried with mirrored checked and not, neither works without having to open the lid. Swapping to and from the mini with the same cable works fine when I attach my wife's also new 13" Macbook Pro to my display. This is a major pita for me, can anyone help?