JVC 26" LCD Flat TV LT=26C31BUE series Shadow lines have appeared on the screen. The main one is slightly curved, about 1" thick and 18" long horizontally about 2/3rds up the screen. Two fainter ones are about 4" above and below this. When the screen is dark the shadows are very noticeable - when bright white, they can hardly be seen. They appear on the screen whether viewing TV or DVDs. Any idea what is causing this and how can they be eliminated?