Names.nsf replicated from old version

Hi All, i hope someone out there may be able to answer my question. It appears that our names.nsf database has been replicated with a very old version of it from one of our spoke servers. This would be the 3rd or 4th time this has happened and I really need to figure out how to prevent this from happening again. We have scheduled replication set up as push pull from all spoke to admin server. default access to the database is Author with replicate and copy documents. Anonymous is reader. Please help!

Subject: Check User Detail

Check Application properties → User Detail on that spoke server - see if possibly a user is replicating old data back to the address book.