Just had an NTL van down the avenue so i accosted the driver when i saw him peering in the cabinet.
I told him about the spiky connection [he had come to change my neighbours dodgy Set Top Box] and his first words were, "yes i can see why".
As we are in a small avenue we are right at the end of the chain if you like, our box has no amplifier booster [my best description] and the signal is weak. Hes reporting it and it should get sorted. As i type its spiking everywhere.
So hats off to van man [ a very helpful bloke], and a big boo hiss too whoever else didnt think of checking it.