My projector requires odd timings, so I had to put a custom ModeLine in my xorg.conf. Did the trick though. Not sure if this would help with your HD resolution, but it's worth a shot. I added the following to the Monitor section of my xorg.conf:
ModeLine "1368x768" 79.603 1368 1440 1464 1768 768 769 783 804 -hsync -vsync
I had the Powerstrip settings for my projector, but managed to find the xorg ModeLine string with a little help from google. I'm guessing your display will be out there somewhere too. Hope that helps.