A customer had a problem with synchronization between 2 domain controllers. Changes on the NETLOGON share on DC1 we’re not synchronized to DC2.

First thing to look for is events in the File Replication Service Event Log. On DC1 I did not find any events being logged but on DC2 I found a couple of warnings with eventid 13508:
The File Replication Service is having trouble enabling replication from DC1 to DC2 for c:\windows\sysvol\domain using the DNS name ad01gimd.directory.gimd.nl. FRS will keep retrying.……

So I restarted the File Replication Service on DC2. After the restart there was no warning anymore, just an informational message eventid 13516 stating:
The File Replication Service is no longer preventing the computer DC2 from becoming a domain controller. The system volume has been successfully initialized and the Netlogon service has been notified that the system volume is now ready to be shared as SYSVOL…….

I did the same service restart on DC1. This did produce a event Error with eventid 13568, stating:
The File Replication Service has detected that the replica set "DOMAIN SYSTEM VOLUME (SYSVOL SHARE)" is in JRNL_WRAP_ERROR.
Replica set name is    : "DOMAIN SYSTEM VOLUME (SYSVOL SHARE)"
Replica root path is   : "c:\windows\sysvol\domain"
Replica root volume is : "\\.\C:"
A Replica set hits JRNL_WRAP_ERROR when the record that it is trying to read from the NTFS USN journal is not found.  This can occur because of one of the following reasons…….

To resolve this error execute the following steps, just make sure you’re not using a post Windows 2000 SP3 Operating System, as this solution is not recommended to  use on this OS:

• open the registry editor and navigate to the key:
  HKLM\SYSTEM\CurrentControlSet\Services\NtFrs\Paramaters
• Create a new DWORD value named: “Enable journal wrap automatic restore”  and give it a value of 1
• restart your File Replication Service

This should produce a warning in your File Replication Service Event log (13560) stating:
The File Replication Service is deleting this computer from the replica set "DOMAIN SYSTEM VOLUME (SYSVOL SHARE)" as an attempt to recover from the error state,
Error status = FrsErrorSuccess
At the next poll, which will occur in 5 minutes, this computer will be re-added to the replica set. The re-addition will trigger a full tree sync for the replica set….

So I gave the server 5 minutes. After that I got some informational messages in the event log (13553, 13554, 13516)

After creating a text file on one of the netlogon shares, it replicated correctly to the other domain controller.
Another problem solved, another happy customer