Our 50" set is vertically compressing the display. When it's first turned
on its compressed at the top and bottom, almost like a letter box except the
top and bottom lines are squished together. As it warms up, the top returns
to normal but the bottom stays compressed so that the bottom 1/6 of the
screen is black. Also, their is noticeable barrel distortion. Nothing
changes when switching between RF and video inputs.

Any idea what could be causing this? (besides the fact that I just finished
a custom cabinet to put it in?)

Thanks.