Vista - Problems after upgrading TFS 2005 to TFS 2008

Hi guys,

I've just done an upgrade on TFS 2005 to 2008. The upgrade didn't
mention any problems, but I've since discovered one!

The TFS Server is now not responding. For instance, if I go here on
the TFS box:

http://localhost:8080/Services/v1.0/ServerStatus.asmx

....I get a "not authorised" error.

Event Viewer has this to say about it:

==================

TF53010: The following error has occurred in a Team Foundation
component or extension:
Date (UTC): 11/06/2008 12:44:41
Machine: TESTTFS
Application Domain: /LM/W3SVC/3/Root/Services-1-128576618609761840
Assembly: Microsoft.TeamFoundation.Server, Version=9.0.0.0,
Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a; v2.0.50727
Process Details:
Process Name: w3wp
Process Id: 3428
Thread Id: 2872
Account name: XXXX\XXXX

Detailed Message: TF53008: The authentication type is not supported.

For more information, see Help and Support Center at
http://go.microsoft.com/fwlink/events.asp.

==================

Any clues?! Thanks in advance,

Steve.