I just got my TV on Friday and I am noticing a flicker when I am watching High Def. I don't seem to notice it any other time. That does not mean it does not happen, but I just have not noticed it yet. That may be because High Def programming seems to stay on still shots more than regular programming. The picture seems to almost pulse (reminds me of a heartbeat). It just seems to darken or lighten very slightly every other second or two. It is barely noticeable until it catches your attention. Even when I come back to it later it takes a minute or two before I catch it again. Sometimes it is more noticeable than others. I seem to notice it more on INHD and INHD2 than other channels. Is this normal? Could it be my TV or my power? Or could it just be the signal? I have the Sony KDF-55WF655. Adelphia Cable with a Motorolla DVR/High Def Cable Box hooked up with Component cables.