Portrait/Landscape problem

I use my 7200 on a copy stand most of the time and the Orientation Sensor has difficulty knowing what to do. Even when this is OFF the image flicks back and forth between the two orientations, making it very difficult to set up a shot. Is there a way to force the camera to stay in one mode?

Many thanks

The Playback menu has a "Rotate Tall" with On/Off, to allow orientation of portrait/landscape pictures on the display.