Got it. Actually the solution is very, very simple; however, no one would think to do this except me (who wrote the 'SWorld' class and maybe a very few others, who are good at deciphering and understanding the code). Add the Heart into the world using 'addObject(Actor, int, int, false);'. The 'false' at the end tells my SWorld class that it is not a scroller object and, in essence, it is not. It is to become the main actor -- the one that controls the scrolling when moved.