Heh...I keep waiting for our John Deere to breakdown to get a zero-radius mower as well.

Your Denon is only driving the fronts and surrounds, and just providing a signal for sound to the sub, but the EP800 runs on its own amp right? That is weird that the Denon amp would have a compatibility problem.

Onkyo TX-NR801
Pioneer CS-J725 4-way fronts
VP180v3 center
Bose 301 Series 3 surround
Sony subwoofer