Dvd video distortion

I own a Toshiba SD 3980SU2 DVD player and a Toshiba 42DPC85 Plasma Monitor…no problems for 3 months…now I get video distortion on certain DVD’s, during play…not in the intro session.Is a line and judder of the screen running horizontally 4 - 5 inches along top of screen .

Any thoughts , help ?