I just received a cable that goes from Mini Diplayport to HDMI. Very nice and all. The problem, the desktop screen appears but nothing else does. My background Pic will show up on the screen of my High Def Samsung TV but nothing else does. The icons at the bottom do not show up nor do any of my open windows. When i open a movie and go to full screen mode the TV goes black. If I open front row the screen goes black and nothing is displayed. What do i need to do to get this to work. It is clear it can work but i must be missing something. Do i need to calibrate, hit F5 like you do a PC. WHAT? Thanks for any help.