error on slapadd updating to 2.3.24 from 2.1.22

[Michael Osten <mosten@iowatelecom.net>]

I've dumped my 2.1.22 ldbm database with slapcat to .ldif and try to  
import into 2.4.24 bdb database.  I'm sure this is a schema problem,  
but I'm not sure how to proceed in fixing it.  More info as  
requested.  Thanks.

= str2entry(ou=people,dc=domain,dc=net,o=base) -> 0xb7c00da0
oc_check_required entry (ou=people,dc=domain,dc=net,o=base),  
objectClass "organizationalUnit"
oc_check_allowed type "ou"
oc_check_allowed type "objectClass"
oc_check_allowed type "o"
Entry (ou=people,dc=domain,dc=net,o=base), attribute 'o' not allowed
slapadd: dn="ou=people,dc=domain,dc=net,o=base" (line=117): (65)  
attribute 'o' not allowed

here is line "117" of my ldif:

dn:  uid=user,ou=people,dc=domain,dc=net,o=base