I made a post in the Home AV Distribution and Networking forum, would probably have been better in this forum. I won't repost now, but if anyone can help I'd be grateful.

Thanks

An addendum after further testing: If I connect the Mac Mini directly to the TV with the 50 ft cable (actually there is DVI-HDMI connector in the loop) I have a perfect picture. Thus the problem seems to be with the Denon receiver. However, if I put a splitter/booster in the loop, no signal to the JVC, but perfect signal to my Sanyo PLV70 projector. Same hookup with a short cable to the JVC, and I have good signal to both TV's. So the problem seems to NOT be with the receiver. I feel like some smart HDMI person out there must be smiling because he knows the answer :) ....................

Does the 'booster/splitter' pass HDCP handshake properly....is it compliant.

I would research the booster/splitter unit for compliance.

Thank you for the answer. The splitter is HDCP compliant. It gives me an excellent picture on the other projector to which the second HDMI cable is connected as well.