When testing a Silverlight application using Rapise, you need to ensure that your Silverlight application does not run in window-less-mode, i.e. set the 'Windowless' property of the Silverlight HTML object to false. Find more information about window-less mode on the following site: msdn.microsoft.com/en-us/library/cc838156(VS.95).aspx
For example if you have the following object in your HTML page:
<object data="data:application/x-silverlight," type="application/x-silverlight-2" width="100%" height="100%">
<param name="Windowless" value="true" />
...
</object>
You will need to change this to:
<object data="data:application/x-silverlight," type="application/x-silverlight-2" width="100%" height="100%">
<param name="Windowless" value="false" />
...
</object>
Then you will be to perform automated testing successfully.