My Hitachi direct view HDTV has an automatic progressive scan upconverter for 480i programming. My Motorola HD cable box also has 480i Override feature which essentially does the same thing but is switchable. With both of these features turned on I get a grainy picture that flickers. These two circuits are apparently bucking each other or something. Does anyone have an opinion on this? I would think that a progressive output from the cable box matched to a progressive input on the TV would be the ideal set up.