Audio goes out when connecting A/V receiver to projector

[alfonso5]

Here is a real puzzler: I have an atsc TV tuner (Samsung SIR-451)connected to my Denon 1513 AV receiver with an AVI to HDMI cable (the tuner doesn't have an HDMI out) for video and with an optical cable for audio. The receiver has no problems recognizing and reproducing the audio and the video. However, and here is the puzzler, when I connect the receiver to my brand new Epson PowerLite Home Cinema 8350 through HDMI, misteriously, the sound goes out (but the video is fine. As soon as I disconnect the HDMI cable from the projector, the audio comes back, but of course, the video goes out! By the way, I also have a blue-ray player connected to the A/V receiver through HDMI (carrying both video and audio) with no problems. Any ideas, would be very much appreciated!