well i seem to have the same sort of problem, some channels (bbc,itv 1/2/3&4, ss1/2/3&X and the movies, so most that i watch) pixelate and others the sound is like it's being interfered with. either way it's unwatchable and it's both on my v+ and old pace box.
and can't get an engie untill tuesday which is pants as it's BH weekend and theres sports that i wanna watch.