I have had this set for a few weeks now and have noticed a few faints vertical lines that  are specially visible watching a football match as the camera pans. the lines are always in the same place. Now because I have become aware of the lines I notice them on most scenes albeit extremely faint on most, but very evident on hd football. Is this common, can it be tweaked? I'm disappointed as I do not expect this sort of thing on a flagship model