Samba - cant enable users for samba

[jtalas]

I have Linux enabled user which I want to enable for samba. But smbbulkadd
shows an error:

bonie2:~ # smbbulkadd -a cn=admin,o=mou -w unis -f /root/samba.txt
==> Processing user list file '/root/samba.txt'
ERROR: linuxUser2SambaUser() invalid USER_INFO
bonie2:~ # cat samba.txt
-u smb -x ou=samba,o=mou -p samba

Do you have any idea how to fix this?
Jakub Talaš