I've just replied to you in the how it works section. Yes, it happened to me too. I'm wondering if it's one of those signals they send to fry illegal cards.
I'm not familiar with NTL, but I suffered the same problem with my DVD player to TV. It was the quality of my scart lead. In this day and age, you get what you pay for. I invested �25 in a gold scart and it cured the problem. Worth a try.