I think previously you set the "16:9 Overscan" to on and so the picture was stretched to fill the whole screen but the picture quality suffered as a result. Now with the "16:9 Overscan" set to off, the picture is reproduced in its original size and the picture quality should be better. So just leave the setting as it is. Mind you there is a slight variation in the size of picture for different movies. It is wrong for you to think the picture should fill the whole screen every time.