I've got the 60LCX63 and it has a "Demo Mode". If your menus are like mine, you can go into Menu - Setup - Other Adjustments, and see if Demo Mode is on.
Just a thought. I haven't tried this mode but maybe yours has this turned on, causing the menu to appear at startup.
Just a thought. I haven't tried this mode but maybe yours has this turned on, causing the menu to appear at startup.