As the All Your Base video meme said, “main screen turn on!”
I got my MythTV frontend working with my HDTV again after a ridiculously tough set of issues to resolve. First, the PC in question is my old Thinkpad laptop and is barely functional to begin with. If you touch it ever so lightly, for instance, the display and keyboard will cease to function. I had to carefully position it through trial and error before I got it to keep its video alive.
Once that was done I was happy to see mplayer doing something on my big screen, only it wasn’t showing any video. GNOME would dutifully draw a border around where my video was supposed to be showing but all there was was an empty box. Instead, the ATI Radeon video driver was showing my video on the laptop screen – the booby-trapped one, remember? No good. No good at all.