I have an Optoma H56 projector that is fully HDTV compatible (native XGA). I have a Samsung H260F HDTV receiver (cable/over the air) that I connect to the projector with a HDMI-to-DVI cable and it works wonderfully at all resolutions. This week I signed up for a Comcast HDTV account and they delivered a Motorola DCH3200 high definition box with HDMI output. I connected this to my projector with the same HDMI-to-DVI output (and RCA cables to stereo for audio). I get sound through the stereo just fine but only a black screen from the projector for video. Some type of signal is coming through because the projector indicates that it is receiving a signal on the DVI -- but the image is entirely black/blank. It makes no difference which resolution output I select on the receiver. Ideas/help much appreciated!

Probably has something to do with the h56 not being hdcp compatable

I have one of these also, use component and set the comcast box to 720p for the best picture. Use your DVI input for computer or look for an old Bravo D1 /bravo D2 which aren't HDCP compliant and work great with the H56.