Event id 1168 Active Directory

In our domain controllers we see below events:

Log Name:      Directory Service
Source:        Microsoft-Windows-ActiveDirectory_DomainService
Date:          19.12.2012 7:13:45
Event ID:      1168
Task Category: Internal Processing
Level:         Error
Keywords:      Classic
User:          "our domain"\XXXX$
Computer:      YYYY
Description:
Internal error: An Active Directory Domain Services error has occurred.
 
Additional Data
Error value (decimal):
1332
Error value (hex):
534
Internal ID:
1240627
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name="Microsoft-Windows-ActiveDirectory_DomainService" Guid="{0e8478c5-3605-4e8c-8497-1e730c959516}" EventSourceName="NTDS Replication" />
    <EventID Qualifiers="49152">1168</EventID>
    <Version>0</Version>
    <Level>2</Level>
    <Task>9</Task>
    <Opcode>0</Opcode>
    <Keywords>0x8080000000000000</Keywords>
    <TimeCreated SystemTime="2012-12-19T05:13:45.180564900Z" />
    <EventRecordID>1621</EventRecordID>
    <Correlation />
    <Execution ProcessID="436" ThreadID="4832" />
    <Channel>Directory Service</Channel>
    <Computer>YYYY</Computer>
    <Security UserID="S-1-5-21-1074365621-3550774200-4067301949-50952" />
  </System>
  <EventData>
    <Data>1332</Data>
    <Data>534</Data>
    <Data>1240627</Data>
  </EventData>
</Event>

XXXX is RODC and YYYY is DC server.