newbie: value of naming attribute 'something' is not present in entry

[Nagy Gabor <linux42@freemail.hu>]

I have a problem:

I have created a schema (the first ever), and when it was working on my
machine I gave it to a guy, to put it on the test machine.
He had some trouble making it work, so he did modify my schema here and
there, but at the end I think the result is pretty close to my version.

However when I try to create an entry on the test machine, ldapadd fails,
and I don't know why.

gnagy@concorde:~/LDAP-tests$ ldapadd -x -f exported.ldif -D "cn=admin,o=client,c=pl" -W
Enter LDAP Password:
adding new entry
"ptkSubscriberMSISDN=501000042,ou=Subscribers,ou=sda,o=client,c=pl"
ldap_add: Naming violation
        additional info: value of naming attribute 'ptkSubscriberMSISDN' is not present in entry

ldif_record() = 64

exported.ldif contains this:
# This file was generated by gq 0.6.0   (http://biot.com/gq/)
# run by gee Mon Nov 24 17:47:59 2003
# subtree search on
# ptkSubscriberMSISDN=501000042,ou=Subscribers,ou=sda,o=client.pl
# server: localhost:389
# binddn: cn=admin,ou=sda,o=client.pl
version: 1
dn: ptkSubscriberMSISDN=501000042,ou=Subscribers,ou=sda,o=client,c=pl
objectClass: ptkSubscriber
ptkSubscriberMSISDN: 501000042

What is wrong?

Another thing:
When I connect with gq to my machine, it says: no schema information found
When I connect to the other machine, it gives me a tree of all the
attributes, classes, etc. that that server knows.

What can be the difference?

Regards,
Gabor