I am having some big troubles with an installation. Let me cut to the chase, the Audioplex plasma proof units are excellent and they work. However, they DO NOT pass thru the frequencies of digital set top cable boxes. Tech support won't acknowledge it and YES, I am using their 4056 receiving block designed for the higher frequency signals. I have 10 components working flawlessly but, this one damn cable box is destroying the whole setup and of course, it is the single most important and used piece of the rack. Any help appreciated.

PS: It is all being run to a Xantech connecting block, but the block isn't the problem because all of the other components are working and the cable didn't work with the Audioplex connecting block either.