Re: Can't get native resolution on Pioneer PDP-507XD via HDMI
I ran into a similar problem with my Sharp Aquos LC26D4U... I've got it hooked up via a DVI-HDMI cable and was getting overscan at 1280x720... I had to add a modeline to xorg.conf and am now running at 1216x684 without overscan.
There's a windows util you can use called Powerstrip (if you dual boot) that will give you all the info you need for a modeline, but I just googled for a 1216x684 modeline and tried them out until I got one that worked.