In 7 years of having the cable service, both analogue and digital, I think I've only had 3 problems since I got it installed, a problem each for Nynex, CWC and NTL. Out of the 3, the worst cs had to be when it was Nynex and that was their fault for mucking me about when installing the cable in the first place. The other two were sorted out no problem.
I'm not an employee of ntl, though people do tend to call me pinnochio for some reason...