When you're in terrain mode you get the little preview window to the left of the main preview window, showing the rough position/orientation of the camera. When the camer is repositioned so it's out of this window you can use the '-' and '+' buttons to zoom out (or in) so the camera is now back in the view.
So here's the problem: Once I've zoomed out so the camera is back in the view the scale is (of course) much larger. I'd like to reset the little preview window so the camera is at it's center again - not move the camera, but reset the boundaries of the little preview. Is there a way to do this?