[flexcoders] Custom Components - updateDisplay results in ghost children drawn

[polestar11]

Hi

I've been working with custom components & only just noticed a strange
re-drawing issue where I get ghost versions of the children in my
component appearing.

I've only just noticed this since I set the child's position relative
to unscaledWidth, which changes and so allows me to see N different
older versions of the child. This is quite worrying because this means
in my other versions where I the child position is static there are
possibly N occurances of my child component.

Why would this ghosting be happening and is there anything one can do
to purge older instances?
Here's a screenshot of the ghosting:
http://img395.imageshack.us/img395/7826/ghostredrawingpq9.jpg

Here's the code:
import mx.controls.Label;
import mx.core.UIComponent;

public class TestComponent extends UIComponent  {
        
        private var label:Label;
        public function TestComponent()         {
                super();
        }
        override protected function createChildren() : void {
                super.createChildren();
        if(!label) {
            label = new Label();
                        label.text = "A LABEL";
            addChild(label);
        } 
        explicitWidth = 200;
        explicitHeight = 200;
        }       
        override protected function updateDisplayList( unscaledWidth:Number,
unscaledHeight:Number ):void {
                super.updateDisplayList(unscaledWidth, unscaledHeight);
                
                label.setActualSize(label.measuredWidth, label.measuredHeight);
        }       
}