Question about lines that appear on television?

I don't know where you get the horizontal lines, but on my TV, I would get horizontal lines at the very bottom and top of the screen.

I fixed this by changing my screen size settings from "screen fit" to "16:9"

It might also be because of the refresh rate on the TV.

How old is your tv? TV's typically have a refresh rate, which is how many times the screen redraws itself in a second. Typical refresh rates are 60hz. Now related to LCD's. LCD's have a what is know as an interlaced rate usually advertised on the model such as 720i. This is about how clear the picture is, the higher the interlaced rate, the better quality picture. Then there is progressive scan, or p, such as 420p. A progressive scan always scans the channels, dvd for changes, and changes the picture instantly. A slower progressive scan will change the picture slower, thus fast scenes such as action scenes are not drawn smoothly and can be affected with imparments such as horizontal lines. Try to see if your model allows you to adjust the progressive scan rate to a higher rate which will achieve a better picture.