I get the following message when trying to change a password for a user I
just created this morning.

(Error -634) The target server does not have a copy of what the source
server is requesting. Or, the source server has no objects that match the
request and has no referrals on which to search for the object.

A couple weeks back I had problems with the servers not being synced. That
is resolved once I config'd them to use timeservers. Also, last couple of
days I
have noticed that it takes a little extra to log me in.

I've gone through the NDS Health Check:
Everything looks ok.
Could you suggest something else I might try?