uidNumber attribute not allowed

["John Green" <green@blueheronbio.com>]

I've posted this question before, but I still have not found an answer or a
solution. Please forgive my ignorance (stupidity?) on the subject, but I am
trying to add the attribute uidNumber. The error I get is "Object class
violation," "attribute not allowed." I have my LDAP/Kerberos integration
working fine, but I need to incorporate LDAP with Samba. All the
documentation I have on this states the uidNumber attribute (gidNumber too)
is required.  I have tried everything I can think of, including dropping the
standard nis.schema and using a custom samba schema that includes uidNumber.
Same error. Can anyone tell me what is going wrong? I know the FAQ states
the attribute is not allowed (obvious), but I would like to know why (not
obvious), and especially if there is a workaround. This problem has stalled
me for an entire week. I've only been working with LDAP for two months, and
although I feel I've gotten pretty far a little insight right now would help
me a great deal. Can anyone give me a hand?