JSI Tip 0632 - Event ID 5711 occurs every five minutes on the PDC.

Event Id 5711 - Source: NETLOGON
Description: The partial synchronization request from the server <BDC> completed successfully. X changes(s) has(have) been returned to the caller.

You may also receive any of the following on your BDCs:

 
Event Id 5730 - Source: NETLOGON 
Description: Replication of the SAM Global Group "Rid: 0x201" from 
primary domain controller  failed with the following error: 
Cannot perform this operation on built-in accounts. 
Event Id 5731 - Source: NETLOGON 
Description: Replication of the BUILTIN Local Group "Rid: 0x220" from 
primary domain controller  failed with the following error: 
Cannot perform this operation on built-in accounts. 
Event Id 5716 - Source: NETLOGON 
Description: The partial synchronization replication of the BUILTIN 
database from the primary domain controller  failed with the 
following error: 
Cannot perform this operation on built-in accounts.

This is generally caused by modifiy the group membership of a built-in account. You may have removed Administrator from the Administrators group on a Domain Controller. You may have:

Made the Administrator's account a non-Administrator account.
Disabled the Administrator's account by clicking the disable account check box.
Set the Administrator's account to expire.
Removed the Domain Admins global group from the Administrators local group.
Removed Administrator from the Domain Admins global group.

To fix the problem, reverse your action(s).