EVENT ID 1202

My client (who has WIN2000 SBS)has a recurring error and warning messages that are occuring every
five minutes in the Application log:
First the warning appears – Source:SceCli, with the description…
“Security policies are propagated with warning. 0x534 : No mapping between
account names and security IDs was done.
Please look for more details in TroubleShooting section in Security Help. ”
Then the error occurs – Source:Userenv, with the description…
“The Group Policy client-side extension Security was passed flags (17) and
returned a failure status code of (1332). ”
I have checked MS Technet, and eventid.com, and implemented their solutions – but nothing has changed. It appears the problem is to with account names, security IDs and security policies. What else can I try?