Nope, that does not seem to be the case, the issue seems to be that the scroll function at some point simply lost it’s fine touch. You either stay light years away from the drawing or race right past it, - the Orbit function still works just fine but lining the zoom tool up and having a bit of fine control seems pretty much impossible, even when you do get down to the actual drawing all it takes is a click too far back or forward on the scroll and you fly back into outer space. It seems as if something is preventing SU in interpreting the input from the mouse properly and since it works just fine on other drawings it points towards something in the specific drawing that causes this behavior without being able to pinpoint exactly what.