title: DataGrid itemrenderer getting issue while scroll
body: <p>I am using radio button inside spark datagrid as following way.</p>
  
  <pre><code>&lt;s:DataGrid dataProvider="{arrList}" &gt;
  &lt;s:columns&gt;
  &lt;mx:ArrayList&gt;
  &lt;mx:source&gt;
      &lt;s:GridColumn width="90" headerText="radio"&gt;
       &lt;s:itemRenderer &gt;
       &lt;fx:Component&gt;
          &lt;s:GridItemRenderer&gt;
                  &lt;fx:Script&gt;
                  &lt;![CDATA[
                      override public function set data( value:Object ) : void 
                      {
                          super.data = value;
                          rdId.group=outerDocument.rbgGroup;
                      }
                  ]]&gt;
                  &lt;/fx:Script&gt;
            &lt;s:RadioButton id="rdId" /&gt;
          &lt;/s:GridItemRenderer&gt;
          &lt;/fx:Component&gt;
          &lt;/s:itemRenderer&gt;
      &lt;/s:GridColumn&gt;
  
       &lt;s:GridColumn headerText="Name" dataField="name" /&gt;
      &lt;/mx:source&gt;
    &lt;/mx:ArrayList&gt;
  &lt;/s:columns&gt;
  &lt;/s:DataGrid&gt;
  </code></pre>
  
  <p>I have created group for radiobutton as i want any one of selected.</p>
  
  <pre><code>&lt;s:RadioButtonGroup id="rbgGroup" /&gt;
  </code></pre>
  
  <p>This working fine. But, if i select any radio like first and scroll then it will select another radio button automatically and first selected removed.</p>
  
  <p>I have checked many other post like <a href="https://stackoverflow.com/questions/22223551/checkbox-itemrenderer-in-datagrid-got-selected-unselected-while-scrollling-in-fl">this</a> but that doesn't seems work.</p>
  
  <p>Issue occurred only when i scroll. <br>
  Any help would greatly appreciated. </p>