[flexcoders] className question

[candysmate]

I have an itemRenderer declared as:

<mx:itemRenderer>
  <mx:Component className ="rendererStyle">
        <mx:Text>
                                                                                
        </mx:Text>
  </mx:Component>
</mx:itemRenderer>

If I use this again elsewhere I get an error 'class name specified
more then once in document'.

But I thought the whole idea behind class names was to be able to
'group' components for styling etc ...?