I'm trying to connect my 5870 via HDMI to my sony sound bar, sony CT500. Then output from the CT500 to my lcd monitor via HDMI. All I see is the background of my screen... What did I do wrong? I'm using Windows 7 64 bit and did download the latest driver update via AMD.
You've turned the HDTV into an extra monitor (try dragging windows from your main computer screen into the HDTV to confirm this). You've basically extended the visual space of your desktop, and usually the taskbar doesn't extend to the other screen.