Cheers guys
Right.....'network' chap turned up......checked levels, tweaked stuff sorted out a few problems he found at the street furniture .....still no joy
He's going to ring around and see if he can find anything out from the chaps further upstream and ring back next week.
On the plus side ntl are doing themselves proud with their speed of response to my problem and on a personal note both engineers said that my diy cable from the wedge to stb is working perfectly
So yaaboosucks to all here that say it can't be done!