[flexcoders] setters on my repeated custom component fire twice

[chuckjr]

I am using a repeater to display thumbnails. The repeated component is a custom 
component includes a setter for the image property. When the setter runs, it 
loads an external image. 

The problem is that when I change the repeater's data provider, it appears that 
the setters for the images fire twice; once when the data provider is changed 
but before the repeater starts, and then again when the repeater runs. 

As a result, each component loads it's image twice, which uses extra bandwidth. 
Plus, if the new data provider has less items than the one it's replacing, the 
existing repeated components that are beyond the number of the new components, 
try to load an image that there is no data for, resulting in a browser error.

This happens weather recycleChildren is true or false. I made a bare bones 
test, and it did the same thing, so I'm guessing this is normal behavior. 

So, what should I be doing differently so that the setters don't fire twice?

Here's the repeater code:
<mx:Repeater id="myRepeater" repeatStart="{trace('repeatStart')}">
        <local:myBox myText="{XML(myRepeater.currentItem).text}"/>
</mx:Repeater>

Here's the custom component:
<?xml version="1.0" encoding="utf-8"?>
<mx:Canvas xmlns:mx="http://www.adobe.com/2006/mxml"; width="100" height="100">
        <mx:Script>
                <![CDATA[               
                        [Bindable]
                        private var _myText:String;             
                        public function set myText(val:String):void
                        {
                                trace("setter called")
                                _myText = val;
                        }
                ]]>
        </mx:Script>    
        <mx:Box backgroundColor="0xFFFFFF">
                <mx:Label text="{_myText}"/>
        </mx:Box>       
</mx:Canvas>