Creation remote DCOM object fails under IIS 7 with System.UnauthorizedAccessException
Type objBlType = Type.GetTypeFromProgID("NetCatService.CatalogServer.1", netCatServerAddress, true);
 instance = Activator.CreateInstance(objBlType);

<system.web>
    <trust level="Full" />
    <identity impersonate="true" password="pass" userName="userName" />
</system.web>