Newer to the silverlight why the map invisible?

kju

I just installed the silverlight 4 tool for visual studio,and the silverlight developer, but the map is alway invisible when running the app,why?
I have installed the arcgis server to the directory :H:\Program Files ,and my clientaccesspolicy.xml is config with:
[HTML]<?xml version="1.0" encoding="utf-8" ?>
<access-policy>
  <cross-domain-access>
    <policy>
      <allow-from http-request-headers="*">
        <domain uri="*"/>
<domain uri="http://*"/>
      </allow-from>
      <grant-to>
        <resource path="/" include-subpaths="true"/>
      </grant-to>
    </policy>
  </cross-domain-access>
</access-policy>
[/HTML]
I event  create a directory "C:\inetpub\wwwroot" and copy the files "clientaccesspolicy.xml" and "crossdomain.xml" inside.
what is the other stuff I shoul do then? Thanks very much.

kju

I solved the unknown problem by reinstall Visual Studio and related silverlight software.