[away3d] stupid problem with light

[jens lofberg]

I have a very strange problem. When I run the code below I get this error:
1067: Implicit coercion of a value of type 
away3d.lights:DirectionalLight3D to an unrelated type 
away3d.core.base:Object3D.

If I remove this line everything works (but no light):
 _view.scene.addChild(_light);

Any idea could be helpful...
thanks / jens

package {
    import away3d.containers.Scene3D;
    import flash.display.Sprite
    import flash.display.BitmapData
    import flash.geom.Matrix;
    import flash.geom.Point;
    import cube.events.InfoEvent;
    import flash.display.DisplayObjectContainer
    import away3d.cameras.Camera3D
    import away3d.containers.View3D;
    import away3d.core.math.Number3D;
    import away3d.primitives.Cube;
    import away3d.containers.ObjectContainer3D
    import away3d.lights.DirectionalLight3D;

    public class TreeDBase extends Sprite {
        public var _items3D = new ObjectContainer3D()
        public var _cam:Camera3D
        public var _view:View3D
        public var _light:DirectionalLight3D

        public function TreeDBase () {
        }
        public function setup3D():void {
            _cam = new Camera3D( { zoom:6, focus:400 } )
            _view = new View3D( {x:0, y:0, camera:_cam, stats:true } );
            _items3D = new ObjectContainer3D()
            _view.scene.addChild(_items3D);
            addChild (_view);
            _light = new DirectionalLight3D();
            _view.scene.addChild(_light);
        }
        public function remove3D():void {
            removeChild (_view);
        }
        public function update3D():void {
            _view.render();
        }
    }
}