There was a thread during beta 4 about this, if I'm thinking of the same thing the OP is reporting. The problem is that some tactical battle maps are larger than the screen or window size, and that if the focus shifts to one of your units, enemy units at the far end of the map can scroll off the window (since the focus centers on your unit). In order to target such an enemy unit for a ranged attack (as an example), you then have to either zoom out until you can see the enemy unit, or click and drag the map until the unit becomes visible. Side scrolling doesn't work, and in my case at least once zooming wouldn't work, I had to drag the map.
