Recently went on a road trip. The wife decided to sit in the second row seat and try out the RSE with the headphones. Great for me, I can listen to my tunes on the radio and she can watch a DVD. Problem: The audio on the headphones fades in and out. First time to try out the RSE, so we thought, hey, maybe we need new batteries (although new batteries were put in before the trip, they had been in the package for a few months.) No dice. Decided to put in new batteries today. Still have the fading in and out of the audio. Any thoughts? Bad line of sight to the transmitter? Too close? Too far? Any help appreciated.