[flexcoders] what is wrong with the following code: datagrid ItemRenderer

[learner]

In the following code :
the last item remain selected.. can somebody help me to debug this. this is
really driving me crazy..

<?xml version="1.0"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml";
creationComplete="init()">
    <mx:Script>
        <![CDATA[
            import mx.collections.ArrayCollection;
            [Bindable]
            public var  initDG:ArrayCollection = new ArrayCollection()
            public function init(){
                var a:Object = new Object();
                 a.Artist = 'Pavement';
                 a.Album = 'Slanted and Enchanted'
                 a.Price=11.99
                 a.Cover='slanted.jpg'
                 initDG.addItemAt(a,0)
                 initDG.addItemAt(a,1)
                 initDG.addItemAt(a,2)
                 initDG.addItemAt(a,3)
                 myGrid.dataProvider = initDG
            }



        ]]>
    </mx:Script>

    <mx:DataGrid id="myGrid" dataProvider="{initDG}"
            variableRowHeight="true">
        <mx:columns>

                <mx:DataGridColumn dataField="Album">
                    <mx:itemRenderer>
                        <mx:Component>
                        <mx:Button label="{data.Album}"/>
                           mx:Component>
                    </mx:itemRenderer>
                </mx:DataGridColumn>

        </mx:columns>
    </mx:DataGrid>
</mx:Application>

Thanks in advance
Regards