I've had the same problem with my Samsung 32" purchased from Dixons. The problem occurred after thirty days from date of purchase and Dixons refused to change the TV and referred me to Samsung. Samsung replaced the LCD screen at the first attempt to repair, but the problem still persists. They have had it back twice since replacing the LCD screen and say they cannot find anything wrong with it and refuse to replace it. They just say it is my Sky box, but I have tried other TV's with my Sky box and everything is ok, so I'm having to live with it. Everyone that sees it asks what is wrong with the TV. No one seems to have an answer.
David Prewitt, February 2009