I'm having a cable grounding problem that causes a dark line to move from bottom to top of the screen. It is only visible during dark scenes. I've discovered that it is the cable tv wire or input that is causing the problem. When I unplug the cable it goes away, but it is annoying to have to unplug the cable before watching a movie. Is there anything that can be done to correct the grounding problem? I live in an apartment so I don't know if the cable company can do anything. Is there an easy fix other than unplugging the cable every time you watch a movie. Thanks for the help.