How come my MovieClip isn't working?

What I'm trying to do is create a series of MovieClips into my flash project (via actionscript) to create a scrolling background. But I'vev run into a strange issue.

For some reason, although I think I am adding the movieclips correctly to the stage, all the variables are set to zero.

Here is the code in my main timeline I am using to create the MovieClips (GrassTile)

var grassHolder:Sprite = new Sprite();

addChild(grassHolder)

for(var i:int = 0;i < 5; i++)

{

    grassHolder.addChildAt(new GrassTile(i), i);

}

(and, if you know a working BBCode to show code, it would also help )

And here is my GrassTile class: I cut out the unimportant stuff. I can add it in later if it is needed.

package  {

    import flash.display.Bitmap;

    import flash.display.MovieClip;

    import flash.events.Event;

    public class GrassTile extends MovieClip

    {

        private var _root:MovieClip

        private var grass:Bitmap;

        public var id:int;

        public function GrassTile(id:int)

        {

            this.x = 100

            this.id = id;

            addEventListener(Event.ADDED_TO_STAGE, onEnterStage);

        }

        public function updateGrassTiles():void //called from the main timeline

        {

            this.x = (0 % this.width) + (this.width * (id));

            this.y = stage.stageHeight - this.height;

            trace(this.width);

            trace(this.x); //These traces return only "0" unless it was the last one created

        }

        private function onEnterStage(e:Event):void

        {

            removeEventListener(Event.ADDED_TO_STAGE, onEnterStage);

            _root = MovieClip(root);

            grass = _root._resource.GrassImage;

            addChild(grass);

        }

    }

}

As I stated in the code comments, when the GrassTiles are added, every one except the last one added returns 0 for its x and width, and doesn't add the Bitmap image.

Thanks in advance!