Creating a Flexible Distribution System, for VM Or Sky

Hi All, New to the forum.

I'm attempting to create a flexible system that will allow distibuted TV around the house, compatible with either VM or Sky+ depending on which option I choose. Currently I have VM.

So far I have 3 CoAx cables from the distribution point to the master point in the Living Room, 2 leading to a quadplex outlet, 1 to the female IEC for the return to dist amp.

In the Cupboard with all the distribution kit, there are all the required CoAx feeds for the sky option, plus the VM CoAx Lead.

My theory was that the VM feed could be split in the Cupboard, using the splitter provided, for Modem and TV. The downlead to the SAT 2 outlet of the quadplex would then be connected to the TV output of the VM splitter.

Sadly, since I've set this up, it doesn't seem to work so well, with a lot of blocking and occasional "This Channel is not available"

Any ideas why? I have used crimped F-type connectors, and decent cable. I thought the SAT 2 outlet was a direct unfiltered connection??

Cheers