Windows2000 Default Domain Policy & NT4

We have a Windows 2000 Domain and have implemented a Dafault Domain Policy. It applies great to Windows 2000 Professional machines, but it does not seem to take on Windows NT Workstation 4.0 machines. The NT 4.0 Workstations are all running Service Pack 6 and are joined to the Windows 2000 Domain.

Can anyone help?