It probably happens with DVDs and other inputs in WIDE mode, just that you haven't noticed it yet. You will always get a little minor bending on widescreen CRTs (horizontal and/or vertical) - 1 cm doesn't sound too bad. You won't be able to correct it in the service menu, as the service menu deals with vertical geometry settings (there are occassionally a couple of horizontal geometry settings in Sony service menus, but they deal with horizontal trapezoid settings, not this sort of problem).