Flex 3 Item renderer in List dissapear and shifted place

Question

I successfully added ItemRenderer in my List but whenever I scroll down to the bottom and scroll up again. The ItemRenderer in the List would be either gone or shifted places.
I have search up on possible solution but they doesn't seen like working. I tried to put dataChange=”validateNow()” in the ItemRenderer but it doesn't work. I read something about useVirtualLayout="false" but it seen like my List doesn't have useVirtualLayout ?
<mx:List
        id="rowsList2" width="{VBoxCall.width}" height="{ scheduleViewerHeight }"
        rowHeight="{ scheduleViewer.rowHeight }"
        verticalScrollPolicy="off" verticalAlign="middle"
         horizontalScrollPolicy="off"
        alternatingItemColors="[0xEEEEEE, 0xDFDFDF]" itemRenderer="RendererState">
        <!-- Example to showcase Item renderer -->
        <mx:dataProvider>
            <mx:Object label="Mr Swabby"
                       data="Juneau"
                       webPage="http://www.state.ak.us/"/>
            <mx:Object label="Mrs Harrington"
                       data="Montgomery"
                       webPage="http://www.alabama.gov/" />
        </mx:dataProvider>
    </mx:List>
Before (picture) http://i.stack.imgur.com/VxoeP.gif
After (picture) http://i.stack.imgur.com/3qHO9.gif
Any Ideas ?
Regards, Mike

Answer 1

Hi Alex,
I've read your blog but I still could find the solution.
I tried to override the set data but it is not working. Whenever I scroll to the bottom and move up again, all the buttons are gone.
Please advise me on this.
Regards,
Mike
<?xml version="1.0" encoding="utf-8"?>
<mx:VBox xmlns:mx="http://www.adobe.com/2006/mxml">   
          <mx:Script>
                    <![CDATA[
                              // Import Event and URLRequest classes.
                              import flash.events.Event;
                              import flash.net.URLRequest;
                              override public function set data(value:Object):void{
                                        if(value != null)
                                        super.data = value;
                                        if(data.label == null)
                                                  Button.label="";
                                        else
                                                  if(data.label == null || data.label=="")
                                                            Button.label = "";
                                                  else
                                                            Button.label = data.label;
                                        else
                                                  myVBox.removeChild(Button);
                    ]]>
          </mx:Script>
          <mx:VBox id="myVBox">
                    <mx:Button id="Button" width="90">
                    </mx:Button>
          </mx:VBox>
</mx:VBox>