Wierd screen problem LCD

[JTR]

I have had my LCD since October 2007. It is a 41 inch Westinghouse. It has had this problem since a little while after I got it but had been annoying me a lot recently.

This happens on both my 360 and PS3 so I know it is my HDTV. I use HDMI. I used to use component on my 360 and it did it then as well.

The best way I can describe it: say I'm playing a game and it switches to a black screen. There will be a line left on either sides or sometimes on the top or just one line. If something takes up the whole screen, the lines will go away. If I watch a blu-ray, at the start when the screen is black and the blue logo comes in from the left, there will be a line left there.

If you need more info I will take pictures. It has gotten really annoying lately.