In the past I migrated some server, added some other node so is possible that a 'ghost' provider CSN is still on the DB ?
Yes. If you have any entries still in the DB that have an entryCSN from your old provider, it will be a valid contextCSN value. If you want that contextCSN gone, you'll need to slapcat your database and modify the LDIF accordingly before re-importing. I assume that was serverID 006, you would want to find all instances of #006# and replace them with one of #001#, #004#, or #005# (so they are consistent) and then reload all servers.
Hope that helps. --Quanah -- Quanah Gibson-Mount Product Architect Symas Corporation Packaged, certified, and supported LDAP solutions powered by OpenLDAP: <http://www.symas.com>