My 811 is hooked up to a Sony LCD HDTV and works fine at 1080i connected via an DVI to HDMI conversion cable. There are standards for these DVI input/outputs and just because they call it DISH DVI doesn't mean it is out of spec with the standard. Although, my experience with IEEE-1394 ( aka i-link, Firewire) has convinced me that digital connections can be a bit finicky.
As mentioned, make sure you are running at least P284 on the firmware.
If you don't have any problems with the component output picture, I would just go that way if you aren't using them for DVD or something.
Best of luck to you.