unrecognized objectClass 'dcObject'!?

[Brian Jones <jonesy@CS.Princeton.EDU>]

How is it possible for this to be 'unrecognized'?!  It's defined in the  
core.schema file, which is specified first on the list of includes in  
my slapd.conf file!  The subject is the error I get when I run the  
following command:

ldapadd -x -D "cn=dapmgr,dc=my,dc=domain,dc=com" -W -f test.ldif

here's the whole error:
------------------------------------------------------------------------ 
-----------
adding new entry "dc=my,dc=domain,dc=com"
ldapadd: update failed: dc=my,dc=domain,dc=com
ldap_add: Object class violation (65)
	additional info: unrecognized objectClass 'dcObject'
------------------------------------------------------------------------ 
------------

here's my slapd.conf file:
====================================
include         /opt/local/etc/openldap/schema/core.schema
include         /opt/local/etc/openldap/schema/cosine.schema
include         /opt/local/etc/openldap/schema/inetorgperson.schema
include         /opt/local/etc/openldap/schema/nis.schema

pidfile         /opt/local/var/slapd.pid
argsfile        /opt/local/var/slapd.args

database        bdb
suffix          "dc=my,dc=domain,dc=com"
rootdn          "cn=daproot,dc=my,dc=domain,dc=com"
rootpw          secret
directory       /opt/local/var/openldap-data
index   objectClass     eq
============================================

Here's the test.ldif file:
============================================
dn: dc=my,dc=domain,dc=com
objectclass: dc0bject
objectclass: organization
o: My Honorable Employer
dc: my

dn: cn=dapmgr,dc=my,dc=domain,dc=com
objectclass: organizationalRole
cn: dapmgr

===============

Any ideas are greatly appreciated.  I've searched google and this list  
and haven't found this same problem.
brian.