I have a scrolling room and I can put the mouse at a part of the screen so that when my character walks towards it, the screen follows him, and stops when my mouse cursor is over a hotspot at the edge of the screen. The cursor changes its view fine (In my game it flashes) and a pop-up bar names the hotspot as is expected.
But this particular hotspot also has a function behind it, to be run when 'Mouse moves over hotspot'. This function is not run when the cursor happns to land on it when the room has scrolled to it. It works fine when you move the cursor youself, but in the case above, it does not.
Hope this helps.
Thinking about it, that would make sense, so I guess this is a bug. I'll get it fixed for a future version.
If it's something that you need to fix urgently, a workaround would be to put some script in the room's Repeatedly Execute to check the mouse co-ordinates and the viewport co-ordinates, and run the code accordingly.
Tracker'd: http://www.adventuregamestudio.co.uk/tracker.php?action=detail&id=523