Open the Active Administrator console.
Expand "Auditing & Alerting".
Select "Event Definitions".
Sort the "Definition Type" column by clicking on the column name.
Scroll down to the "FSMO" event for "RID Master Changed" and disable it.
Uninstall and reinstall the agent on the 2003 domain controller.
Wait until all of the FSMO events stop coming in, and then re-enable the FSMO event.