 			percentWidth = 100;
 			percentHeight = 100;
 			
-			this.addChild(plotBitmap);
+			this.addChild(_plotBitmap);
 			
 			// make selectionFilter appear in session state.
 			registerLinkableChild(this, selectionFilter);

		{
			//trace("sizeChanged",unscaledWidth,unscaledHeight);
			
			var bitmapChanged:Boolean = PlotterUtils.setBitmapDataSize(plotBitmap, unscaledWidth, unscaledHeight);
			if (bitmapChanged)
				invalidateDisplayList();
		}

		{
			// clean up everything that does not get cleaned up automatically.
			disposeObjects(
				_plotBitmap.bitmapData
			);
			if (!usingExternalSpatialIndex)
				disposeObjects(spatialIndex);
