I have a pretty common problem, but I haven't found a solution to it yet. I connected an iMac (mid 2007) to a HDTV with mini-dvi to dvi to hdmi. It seems to work. I use extended display mode and desktop shows on both display. The problem is that I don't get full screen on the HDTV, even though Mac says that the resolution is 1920x1080. I get black lines on every border. I tried with a new Macbook (same connections, same settings) and it worked full screen on both display right after plugging it. Any solutions? Thanks in advance.