I have a new client with Server 2000 and 6 XP Workstations.  He recently
performed a Update to Service pack 4.  After thise update everything worked
fine for 24 hours.  Then, seemilnlgy at random, the XP workstations start
having permissions issues, can't print etc...

The logs on the server show no error.  The Workstations are all getting
these errors:

08/21/2008 1:22:45 PM AutoEnrollment Error None 15 N/A WORKSTATION4
Automatic certificate enrollment for local system failed to contact the
active directory (0x8007054b).  The specified domain either does not exist or
could not be contacted.
 Enrollment will not be performed.
08/21/2008 1:22:44 PM Userenv Error None 1054 NT AUTHORITY\SYSTEM
WORKSTATION4 Windows cannot obtain the domain controller name for your
computer network. (The specified domain either does not exist or could not be
contacted. ). Group Policy processing aborted.
08/21/2008 1:22:29 PM Userenv Error None 1054 NT AUTHORITY\SYSTEM
WORKSTATION4 Windows cannot obtain the domain controller name for your
computer network. (The specified domain either does not exist or could not be
contacted. ). Group Policy processing aborted.
08/21/2008 1:22:06 PM SecurityCenter Information None 1807 N/A WORKSTATION4
The Security Center service has been stopped.  It was prevented from running
by a software group policy.

If I run gpupdate.exe it fixes the symptoms for a day and then they
re-occur.  even a reboot will stop the symptoms for 1-1.5 days, even though
the errors remain.

I have tried These solutions:

http://support.microsoft.com/kb/260575

and

netdom reset <ComputerName> /Domain <DomainName> /UserO <UserUPN> /PasswordO *

The DNS has also been rebuilt without any resulting change.

If you have a fix that lasts longer than 24 hours please advise.