Ok, I have a cable for thunderbolt ----> HDMI and it has worked well up until today I tried to use it and it didnt work. It will detect whatever tv/monitor that I have in.. I have gone into managing and arranging the displays and still no picture. I have no idea what is wrong. For example Connect to Panasonic TV it will show PansonicTV0 and allow me to choose 1080p and even when I connect the cable it flashes blue screen on both the Macbook Air and the extended display then goes away and has no signal detected. Running Lion OS fresh install.. This is the only thing that has changed in the last couple weeks and makes me think the only variable that could have gone wrong? Any help would be appreciated. I am about to buy an appletv and upgrade to Mountain Lion as this is really frustrating!