How can I remove a "Phantom" DFS Namespace Server?

I have two Namespace Servers that failed and were decomissioned, but still appear in my Domain based DFS.  They appear in the "DFS Management" MMC snap-in and when using various command line utilities.

My home domain has Windows 2003 R2, Windows 2008, and Windows 2008 R2 servers which are Namespace Servers.  As I play with my servers, they can fail on me in a way that cannot be recovered, so I have to remove them from the domain and clean up the meta data. 

I have tried to remove the decomissioned servers from DFS, but have not been able.  I have tried the MMC snap-ins, and all the DFS command utilities i could find:  dfscmd.exe, dfsutil, dfsdiag, and dfsdiag.  I tried exporting the configuration and removing the root entirely, but could not remove it (file not found, etc.).

I have looked in the Directory, using Advanced Features, under <domain>\System\Dfs-Configuration and DFSR-GlobalSettings, using the Attribute Editor tab in properties.  I found where the removed servers were referenced in Dfs-Configuration\DFSroot properties.  I edited them out and the change was replicated.

But the missing servers are still in DFS.  I cannot find any other references to them, in the Directory, the Registry, or in files.  It must be a database file somewhere, but I don't know where to look.

If anyone could help me remove these servers from DFS, or at least tell me where that configuration information is located, I would really appreciate it.

Thanks, in advance,

Brian