Help - sound but no picture - Xbox hdmi to DVI

I have been running a Panasonic PTL300U projector (4+ years old). It is pre-HDMI, but it has a DVI input.

I recently upgraded my receiver to a Denon 889 and hoped to take advantage of the HDMI switching capabilities. I run a "Popcorn Hour" media streamer and my upconverting Sony DVD player into the receiver from their HDMI outputs and through an HDMI cable from the Denon to the projector with an HDMI/DVI converter plug. These two devices work flawlessly with the Denon doing the sound duties and switching the video to the projector. The problem I have is with a new XBox360. I have it hooked up the same way as the other two devices, but I get audio, but no video signal to the projector. I checked the HDMI output and cable by plugging it into my plasma in the family room, and everything is good. I understand that HDCP content (blu ray) cannot be passed through the HDMI cables to the DVI port on this projector, but I dont think Xbox games have HDCP. The Xbox is currently working by sending component into the Denon, which converts it to HDMI and sends it off to the projector, but I was hoping to keep the signal all digital if possible. Any ideas? Thanks.

just figured it out (sort of). I plugged the xbox into the plasma and reset the HD resolution to the lowest setting (640 x 480 I think). Shut it down, plugged it into the projector and lo and behold I had video and audio through the receiver. I changed the resolution to the native rez of the projector 720p) and everything is good.

The xbox must have somehow set its resolution to something my projector could not recognize. Anyway - all is well, and I am finally free from those nasty old component cables.