Page 1 of does the philips have picture problems with anamorphic discs ?

I have had a philips dvd 711 for a few months now and have been very pleased with the picture generally. However I have bought a few discs that appear to have the same picture problems and wonder if this is due to the fact that they are anamorphic. The discs are the Mask and the Wedding Singer. Also I have recently bought Demolition man. The problem is with shimmering, at least that`s what I think you call it. When the picture moves quickly, there is like a sort of blocky movement to it then when the picture is not moving, it returns to normal, i.e. if the picture is panning around a room, as in the bar scene in the Wedding Singer, the background wood panelling, seems to move. Demilotion man is even worse. I think that the mask and wedding singer are anamorphic but not sure about demolition man. I have a new Grundig widescreen tv, and using RGB from scart. Most other dvd`s I have look excellent except for these titles.
Does anyone know if it is because the discs are anamorphic ? Has anyone else experienced these problems at all. Is it just bad production of the discs ? Any clues. Thanks