First dial the antenna all the way down and see what happens. I've had a many jobs where the leaving the antenna set where it comes out of the box is too high and some components won't work. Then you can try removing the antenna from the RFX-150.

I realize the ID has to be left on 0, but if you're the cuious type like I am try setting up the routing and set the ID to something other than 0 and see if the DVD comes around.

Sony is usually really good about not overloading, but without routing I suppose it could be overloading, maybe you could mask some of the stray IR with a niles IR blocker (or equivelant) so even though all flashers are flashing the DVD would only see what was coming from it's flasher.

Also, if it is overloading, try unplugging the IR emitter for the DVD and see if the flooding from the other emitters will operate it.

Just a few ideas... keep us posted