Reporting Services 2008 CrossDomain.xml

Hi,

I am trying to create a silverlight application that calls the ReportExecution2005 webservice and it seems that silverlight wants a CrossDomain.xml file at the root of the domain hosting the ReportExecution2005 webservice.  In reporting services 2005 I can add the CrossDomain.xml to the root of the app pool hosting the webservice through IIS but I can't figure out how to add it in SSRS 2008 since the web service is hosted by Sys.Http.  Does anyone know how I would add the CrossDomain.xml in SSRS 2008?

Thanks,

Eric Nelson