Sep 24 11:08:37 kyo slapd[2296]: syncrepl_message_to_entry: rid=001 mods check (postalAddress: value #0 provided more than once)
Sounds like you have bad data in your database that 2.4 catches and 2.3 doesn't.
--Quanah -- Quanah Gibson-Mount Principal Software Engineer Zimbra, Inc -------------------- Zimbra :: the leader in open source messaging and collaboration