Thanks, Adam

I was afraid of that, but see what made me think otherwise.

"the slapd(8) runtime configuration in 2.3 (and later) is fully LDAP-enabled and can be managed using the standard LDAP operations with data in LDIF."
- I have slapd 2.4.9

"but must be converted to the new slapd-config(5) format to allow runtime changes to be saved".
- I did that, but I really don't have the slapd-config man page

in /etc/default/slapd there were already a coment about the the cn=config backend

# Default location of the slapd.conf file. If empty, use the compiled-in
# default (/etc/ldap/slapd.conf). If using the cn=config backend to store
# configuration in LDIF, set this variable to the directory containing the
# cn=config data.

And, after all, I've already deleted slapd.conf and authentication is being made with slapd.d/

Please forgive me for insisting. Thanks
Are you sure it can't be a matter of ACL, admin authentication, or something else?

I'll upgrade to lucid, but it may take a couple of months.