Part of The Menu is cut off of the screen

Hi. Part of the menu is cut off of the screen and i dont know how to fix it, and its really hard to navigate through On Demand. On the Guide its cuts off the channel name(like the 3-5 letter abreviation of the channel) and the time at the time is cut off to and i would really like to know how to fix it. I have used the ZOOM feature, but it doesnt help the Menu. Thanks! Oh, my tv is SD and i watch SD channels