Error while deploying MS chart :Error executing child request for ChartImg.axd.

Question

I am getting this error message when deployed a ASP.NET 3.5 page which renders a chart

Error executing child request for ChartImg.axd.

Then page works well when i run via the VS 2008 IDE.

the below is my web.config

<?xml version="1.0"?>
<configuration>
 <appSettings>
  <add key="ChartImageHandler" value="storage=file;timeout=20;dir=c:\TempImageFiles\;" />
 </appSettings>

  <connectionStrings/>
  <system.web>   
 <pages>
   <controls>
     <add tagPrefix="asp" namespace="System.Web.UI.DataVisualization.Charting"
     assembly="System.Web.DataVisualization, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
   </controls>
</pages>
  <compilation debug="true">
    <assemblies>
     <add assembly="System.Web.DataVisualization, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
    <add assembly="System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
  </assemblies>
 </compilation>

  <httpHandlers>
    <add path="ChartImg.axd" verb="GET,HEAD,POST" type="System.Web.UI.DataVisualization.Charting.ChartHttpHandler, System.Web.DataVisualization, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/>

  </httpHandlers>
  </system.web>
  <system.webServer>
    <handlers>
      <add name="ChartImageHandler" preCondition="integratedMode" verb="GET,HEAD,POST" path="ChartImg.axd" type="System.Web.UI.DataVisualization.Charting.ChartHttpHandler, System.Web.DataVisualization, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
     </handlers>
  </system.webServer>
 </configuration>