This appears to be one of those spurious messages in the logs.. As far as I can tell, samba is not configured in any way to consider there is a domain master browser anywhere present on the network, yet it searches for one and then complains (with default debug level) about the obvious: nmbd/nmbd_browsesync.c:find_domain_master_name_query_fail(353) find_domain_master_name_query_fail: Unable to find the Domain Master Browser name KENNEDY<1b> for the workgroup KENNEDY. Unable to sync browse lists in this workgroup. (This isn't the only spurious log message samba produces. Bug 1257 is another one; one suggestion is to consider a "suppress spurious log messages" option for smb.conf which disables this and that other crazy message.)
marking as later until we revamp Samba logging.
Two years have passed, seems time to reopen.