Bad search filter (-7)

[Michael Oliver <ollie@alariussystems.com>]

I am setting up OpenLDAP and following the guidance from
http://www.openldap.org/doc/admin23/quickstart.html

The uncommented lines from my slapd.conf are:

ucdata-path		./ucdata
include		./schema/core.schema
include		./schema/cosine.schema
include		./schema/inetorgperson.schema
include		./schema/nis.schema

pidfile		./run/slapd.pid
argsfile		./run/slapd.args

database		bdb
suffix		"dc=invent,dc=albanynanotech,dc=org"
rootdn		"cn=Manager,dc=invent,dc=albanynanotech,dc=org"
rootpw		secret
directory		./data
index			objectclass eq

I have it running as a service and I can see via the date time stamps on the
bdb files in the ./data directory that the database is running.

However following the guide I try 

ldapsearch -x -b '' -s base '(objectclass=*)' namingContexts

and I get:

# extended LDIF
#
# LDAPv3
# base <''> with scope base
# filter: '(objectclass=*)'
# requesting: namingContexts
#

ldapsearch: ldap_search_ext: Bad search filter (-7)

instead of what I expected based on the guide:

      dn:
      namingContexts: dc=invent,dc=albanynanotech,dc=org


What am I doing wrong, I have read and re-read the instructions.
	
Mike Oliver