Creating the Active Directory Certificate Services wizard has failed because the Certificate Server interop assemblies could ...

Creating the Active Directory Certificate Services wizard has failed because the Certificate Server interop assemblies could not be found.  Are the interop assemblies (microsoft.certificateservices.setup.interop.dll and microsoft.certificateadministration.interop.dll) GAC'd?  If so, are they GAC'd with the proper version number (it should be the Windows build number)?  Does the version of RMT match the Windows version?