Thanks for reporting. The crash actually occurs when the game window is wider than the level and the minimap is clicked; it has nothing to do vertical scrolling. It even occurs if the level has no vertical scrolling at all. (This can easily be reproduced with the Genesis levels, which are only 1,022 pixels wide as opposed to 3,200.)
This has been fixed for the next release, which should be out very soon (either today or tomorrow).
