Cocos2d v2 + Chipmunk : Fails when adding shapes to a CCLayer
===

I'm very experienced with Cocos2d and Box2d, and wanted to try Chipmunk instead. Everything works fine as long as I add sprites to the helloworldlayer, but if I add another layer and attempt to add a sprite to that new layer it crashes.

It fails with an EXC_BAD_ACCESS in the cpSpaceStep function call in the update on the main layer. 


    -(void) update:(ccTime) delta
    {
    	// Should use a fixed size step based on the animation interval.
        
    	int steps = 2;
    	CGFloat dt = [[CCDirector sharedDirector] animationInterval]/(CGFloat)steps;
    	
    	for(int i=0; i<steps; i++){
    		HERE -> cpSpaceStep(space_, dt);
    	}
       
    }