I have a AMD computer I built myself. Its Windows 7 x64. I have a AMD video card HD 7800 Series. I use two monitors. When I use the HDMI port (on the video card) the computer has a black screen with a movable mouse cursor after booting. I can attach the monitor to the HDMI port after I boot and it works but not if I attached before. If I disable the video driver it works. If I start in safe mode it works.
I have a similar AMD build with a AMD 7700 card and does the same thing. I have tried reloading different drivers several times with no fix. Have you heard of such a problem.
I forgot to mention that I have monitors in the DVI ports that have no problem.
Edit: both HDMI cables are connected to HDTV not monitors.If I disconnect the HDMI cable from the HDTV the video to the other monitors connected
via DVI or VGA will then perform normally.