Error to add objectClass to entries

Hi,

I'm new to this mailing list and I've a question concerning python-ldap.
I want to add some objectClass and attributes to existing entries but I have
this error :
ldap.OTHER: {'info': 'no structuralObjectClass operational attribute',
'desc': 'Internal (implementation specific) error'}

I'm using the add_s() function and I don't know if this is the good for
doing that.

PS : When I use the ldapmodify command with a ldif file and with the same
attributes than in my python code, it works.

You're help will be welcome, Thx

Steeve Barbeau
http://steeve-barbeau.blogspot.com/
http://twitter.com/steevebarbeau