Connection Error: The specified user name does not exist...

I'm having issues making a connection to a specific server that I am unable to find details for or replicate with other servers.

When attempting to connect to this particular server through TS 2008, the following error is returned:

Remote Desktop Disconnected
The specified user name does not exist.  Verify the username and try logging in again.  If the problem continues, contact your system administrator or technical support.

The destination server is Win2K8 x86 Ent and the client making the connection is Vista x64 SP1 and SP2.  I'm able to use the same TS gateway from other clients to the same destination server without issue.  I'm also able to make connections to other servers from the client in question.  It just happens that the one particular server that I need this connection to work for, I get the error noted above.

If anyone has encountered this or can provide some insight, it would be greatly appreciated.

Thank you...

ANVIL