Maya V9 / Collada /Error #1009

Hello everybody

First try and first message :wink:

I have exported a simple cube from maya with collada export plugin.
(version COLLADAMaya_0.9.5.463)

I am trying the tutorial from http://www.gotoandlearn.com/play?id=106

I am using this version of papervision :
Papervision3D Public Alpha 3.0 - PapervisionX (18.09.08)

Here is the compiler error. Does somebody experienced this problem before ?

DisplayObject3D: pCube1
TypeError: Error #1009: Il est impossible d’accéder à la propriété ou à la méthode d’une référence d’objet nul.
at org.papervision3d.objects.parsers::Collada/buildObject()
at org.papervision3d.objects.parsers::Collada/parseGeometry()
at org.papervision3d.objects.parsers::Collada/parseNode()
at org.papervision3d.objects.parsers::Collada/parseScene()
at org.papervision3d.objects.parsers::Collada/buildCollada()
at org.papervision3d.objects.parsers::Collada/onComplete()
at flash.events::EventDispatcher/dispatchEventFunction()
at flash.events::EventDispatcher/dispatchEvent()
at flash.net::URLLoader/onComplete()

Here is my code :

package 
{
	import flash.display.Sprite;
	import flash.events.Event;
	
		
	import org.papervision3d.cameras.Camera3D;
	import org.papervision3d.view.Viewport3D;
	

	import org.papervision3d.objects.parsers.Collada;
	import org.papervision3d.render.BasicRenderEngine;
	import org.papervision3d.scenes.Scene3D;

	
	public class MyCollada extends Sprite 
	{
		private var scene:Scene3D;
		private var vp:Viewport3D;
		private var cam:Camera3D;
		private var bre:BasicRenderEngine;
		private var collada:Collada;
	
		public function MyCollada ()
		{
			setupPV3D();
			addCollada();
			addEventListener (Event.ENTER_FRAME, loop);
			
		}
		private function setupPV3D(): void
		{
			scene=new Scene3D();
			cam=new Camera3D();
			vp=new Viewport3D();
			bre=new BasicRenderEngine();
			addChild(vp);
		}
		private function loop(e:Event):void
		{
			bre.renderScene(scene,cam,vp);
		}
		private function addCollada():void
		{
			collada=new Collada("cube.dae");
			scene.addChild(collada);
			
		}
	}
}