I've just bought a Thomson DHD4000, and a Philips 28PW6518 television. I have a fairly modern ariel, it is a "death ray" sort of liiking thing, which I think is called a "wideband" ariel. The ariel goes into the DHD4000, thence to the TV, & there's a Scart lead between the two as well. Nothing else is connected. Sometimes, I get a rather "jerky" picture... it seems to freeze, then resume a second or two later (losing what's happened in between times, to the eye, anyway). Why might this be happening?