row count in datagrid

Hi All

rowCount property of datagrid not working.

Any suggestions?

<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" backgroundColor="white" layout="vertical" viewSourceURL="srcview/index.html">  

<mx:Array id="arr">

  <mx:Object articleName="Finding out a characters Unicode character code" data="15" />

  <mx:Object articleName="Setting an icon in an Alert control" data="14" />

  <mx:Object articleName="Setting an icon in a Button control" data="13" />

  <mx:Object articleName="Installing the latest nightly Flex 3 SDK build into Flex Builder 3" data="10" />

  <mx:Object articleName="Detecting which button a user pressed to dismiss an Alert dialog" data="9" />

  <mx:Object articleName="Using the Alert control" data="8" />

  <mx:Object articleName="Formatting data tips in a Slider" data="7" />

  <mx:Object articleName="Downloading the latest Adobe Labs version of Flex 3 SDK/Flex Builder 3 (codename: Moxie)" data="6" />

</mx:Array>

<mx:ArrayCollection id="arrColl" source="{arr}" />  

<mx:DataGrid rowCount="9" id="dataGrid" dataProvider="{arrColl}" variableRowHeight="true" width="100%" height="100%">

  <mx:columns>

   <mx:DataGridColumn id="articleName" dataField="articleName" headerText="Name of the article in question" wordWrap="true" />

   <mx:DataGridColumn id="data" dataField="data" headerText="ID of the article" />

   <mx:DataGridColumn id="data" dataField="data" headerText="ID of the article" />

   <mx:DataGridColumn id="data" dataField="data" headerText="ID of the article" />

   <mx:DataGridColumn id="data" dataField="data" headerText="ID of the article" />

   <mx:DataGridColumn id="data" dataField="data" headerText="ID of the article" />

   <mx:DataGridColumn id="data" dataField="data" headerText="ID of the article" />

   <mx:DataGridColumn id="data" dataField="data" headerText="ID of the article" />

  </mx:columns>

</mx:DataGrid>  

</mx:Application>