full scenario: http://www.greenfoot.org/scenarios/5137 in the world class (black_background) there is a scroll() method. it builds 2 lists and attempts to scroll them all. sprites and obstacles if i comment out sprites, the obstacles work fine, the world scrolls and so do the platforms. however, all of the other sprites stay in place. if i try to load the sprites list, it gives me an actor not in world error (actor.getx) trying to fi gure out what's wrong with my code to make sprites not work...