I just got started on GalCiv II and was working through the first campaign mission when the edge scrolling started acting up. Whenever I try to edge scroll, the view jumps to off the map and tries to continue moving up while the game tries to make it return within map boundaries. This results in a bizzare shaking of the screen, which only displays the background.
I'm on a 64 bit system, so perhaps that has something to do with it, but it wasn't a problem for the first few minutes of the game.