I recently added a Denon AVR-1913 to my system. All HDMI hook ups work great with the exception of the Uverse HDMI connection. The connection keeps going in and out for the video, sound is still great. I have changed HDMI ports, changed cables and nothing has helped. My Uverse box is the VIP1216. Is there a compatibility issues between the Denon and the Uverse box? Please help with any advise.