Issue with CF11 - .net service

We installed a new CF11 server on a win2008 with iis7. the .Net ver is v2.0.50727
We have this code :

<cfobject

  type="dotnet"

  class="System.DirectoryServices.DirectoryEntry"

  assembly="#dllPath#"

  name="site">

to allow us to contact to the IIS directory to later create a Virtual Directory on it.
On the prev CF9/2008/iis7 /.net v2.0.50727 this worked great.

ON the new server I get this error :
Ensure that the DotNet agent is running and you have provided the correct host and port information-DotNet Side does not seem to be running.

We made several checks to make sure that the .NET integration with CF works - and it seem to be installed and running

ANY suggestions will be highly appreciated

Thanks