Computer Browser service on a Win2k3 Server Forest

We have 4 domain controllers in a forest all running win2k3 server with sp1. All the backup domain controllers are reporting an error with event id of 8032: “The browser service has failed to retrieve the backup list too many times on transport \Device\NetBT_Tcpip_{hw id}. The backup browser is stopping.” This error does not appear in the logs for the primary domain controller. Anyone have any suggestions as this is driving us crazy? Checked registry on PDC and IsDomainMaster is set to false but we would like to avoid registry hacking if possible. Thanks in advance.