I've solved the interference problem. Tweeterguy hit the nail on the head. Why not use UTP from the get go! Why doesn't URC provide it as part of the package? CAT 5/5e/6 is cheap. Real cheap!

There's already been discussion on this issue in the past and the consensus seems to be UTP to sovle the interference. URC even recommends a specific wiring scheme for connecting CAT 5 cable to the RFX-250s.

I just think it should be part of the package. I'm just whinning. I've solved my problem but I think it would make other installer's problems less likely if they included the cableing with the units.