It is not uncommon for sets from the factory to have screen geometry and/or positioning misadjustments, and it is possible that you are seeing this (e.g. the picture is too high).
If this is indeed the problem, it should be possible to fix this in the service menu by adjusting the proper variables. (I am not sure what the names of the variables will be, but they will probably be something like HPOS, VPOS, HIT, and WID).
Having a calibration disc like AVIA or Digital Video Essentials will help if you want to adjust things, since these discs contain test patterns that you can use to get the image centered properly.
CAUTION: don't change anything in the service menu without first writing down all of the original values.