Cannot create DFS Namespace - RPC server unavailable

I have a test lab of Hyper-V machines.

1 DC and 2 server 2008 members - all running 2008 R2

I am trying to crate a DFS namespace on the DC.

I have installed the File Server role with DFS and File Server Resource Manager roles also installed.

I didnt create a namespcae when installing DFS i chose the option to create 1 later

When trying to create a domain-based namespace on the DC from the Namespace node in Server Manageri get the following error on the Namespace Type page of the New Namespace Wizard:

Working: Validating Input

Error: \\domain.com\DFSTest: The namespace cannot be queried. The RPC server is unavailable

I have tried the following:

1. Disabled firewall incase it was blocking RPC traffic.
2. Checked all RPC services are actually running
3. Removed a namespace1 entry that appeared from Namespaces node in SM, ADSIedit and the registry as per these links
http://social.technet.microsoft.com/Forums/en/windowsserver2008r2general/thread/58f14a60-673c-4dcc-8d0c-be0a4ae190fe
http://developers.de/blogs/ivan_lucic/archive/2009/06/08/dfs-namespace-management-the-namespace-cannot-be-queried-the-rpc-server-is-unavailable.aspx

I cannot find anything else out about this.

Anybody have any suggestions on what i can try next?

Id like to remove the DFS role but i cannot as i have to remove AD first to do so!

Cheers