ADFS Authentication Failure During Domain Controller Reboot; Failure Audit 500 and LSASRV 40960 logged

Consider the following scenario:

• Authentication that relies on Active Directory Federation Services (ADFS) is failing.

• You notice that one or more domain controllers are being rebooted at the time of the ADFS authentication failures.

• The following event is logged in the System log:
  
  Event Type:       Warning
  Event Source:    LSASRV
  Event Category: SPNEGO (Negotiator)
  Event ID:           40960
  Date:                8/25/2009
  Time:                10:05:40 PM
  User:                N/A
  Computer:         ADFSACCOUNT
  Description:
  The Security System detected an authentication error for the server ldap/adatumdc.adatum.com/adatum.com@adatum.com.  The failure code from authentication protocol Kerberos was "The specified user does not exist. (0xc0000064)".
  
  For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
  Data:
  0000: 64 00 00 c0               d..À
  
  
• When ADFS auditing is enabled, the following event will be logged in the Security log:
  
  

  Event Type:  Failure Audit
  Event Source:  ADFS Federation Service Auditor
  Event Category:  Object Access
  Event ID:  500
  User:  adatum\adfsaccount
  Computer:  ADFS1
  Description:
  Transaction ID: {03838d48-ed18-4c12-bb25-d6461ffe2736}

  A token request was received directly by the Federation Service. The request for target 'urn:federation:adatum.com' was denied, and no tokens were issued.  The request was denied because the inbound evidence could not be verified.
  Target URI: urn:federation:adatum.com 

  No resource token was issued. 

  No logon accelerator token was issued. 

  The client did not present a logon accelerator token as evidence. 

  The client credentials could not be verified because of a Lightweight Directory Access Protocol (LDAP) error.
  Account store URI: urn:federation:activedirectory
  Error code: 0xFFFFFFFF8007203A
  LDAP Server: 
  Authentication method: Windows integrated authentication
  Username: adatum\0057401 

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

For more information about configuring ADFS servers for troubleshooting, visit the following Microsoft Web site:

http://technet.microsoft.com/en-us/library/cc738766(WS.10).aspx