Keep us posted zamma!
Suprising Fujitsu were very quick in responding. They had someone out just after lunch to check it out.
After some testing they have said that my Video Distribution Unit (Amplifier) is faulty. So I have contacted the builder and awaiting a call back to see when they can replace it.
When fujitsu left, they told my wife that it is all fixed with a splitter box, but sure enough the srop of signal happened again. I am not at home to see what they have done, so I will check it out in a couple of hours.