Installers please help - Aftermarket DVD - headphone problem?

[rdhoss]

We just bought a 2007 Expy EL (Eddie Bauer), and we had our dealer install an aftermarket DVD player. It's a flipdown unit installed just above the rear of the front console. The player came with 2 wireless headphones. We've noticed bad reception with the wireless headphones. In the second row, you have to sit up, within just a foot or two of the DVD player, to get sound. If you rest your head against the head rest, then it's too far away from the player and the sound is gone. This is unacceptable, of course. We will be taking it back to the dealer, but I wanted to check here if anybody else is familiar with this problem, and if there is some kind of range setting on the DVD player that I can adjust? Any thoughts would be appreciated. Thanks, Ron