In the upper right corner of the Atlas map area, is a vertical rectangular control panel divided into three segments. In the top segment there's a "+" sign, in the middle segment there's a "-" sign, and in the bottom segment there's an "up" arrow and a "down" arrow.
The "+" and "-" buttons zoom the map in and out as I would expect. But the "Up" and "Down" arrow buttons do nothing, and the "Down" arrow button is always grayed out. What are the arrow control buttons for?