Ubuntu – Setting up OpenLDAP for OpenSSO (OpenAM) under Ubuntu

I've got OpenAM (was OpenSSO) installed successfully and running in a Glassfish container. I also have OpenLDAP installed and working minimally. Now I'm trying to import an LDIF file of records from another server (Java Access Manager and Sun Java System Directory Server), but I get a persistent error when I try to run ldapadd:

ldap_add: Invalid syntax (21)
    additional info: objectClass: value #2 invalid per syntax

I've added the schema provided at http://blogs.oracle.com/indira/entry/using_openldap_as_user_data, but it doesn't seem to affect the error message. It could be that I'm missing some simple understanding about LDAP!

Here's an example record from my LDIF file (domain and password changed):

dn: uid=amAdmin,ou=People,dc=domain,dc=org
objectClass: inetuser
objectClass: inetorgperson
objectClass: organizationalperson
objectClass: person
objectClass: top
objectClass: iplanet-am-managed-person
objectClass: iplanet-am-session-service
objectClass: iplanet-am-user-service
objectClass: iPlanetPreferences
objectClass: inetAdmin
objectClass: sunAMAuthAccountLockout
inetUserStatus: Active
cn: amAdmin
sn: amAdmin
userPassword:: ------
uid: amAdmin

I assume that the schema file provided in the link above should contain configuration for all the attributes that are used in the "objectClass" lines, but that could be one of my core misunderstandings!

Thanks for any help!