When my record has been created Odoo warns me with that :

WARNING DevNJA openerp.models: Comparing apples and oranges: res.partner(2973,) == 'Aucun' (/usr/lib/python2.7/dist-packages/openerp/models.py:5600)

This is an example of how I use the 'create' method :

self.env['res.partner'].create(
            {
                'name': nameFmt,
                'firstname': self.firstNameOfUser.strip().lower().title(),
                'lastname': self.lastNameOfUser.strip().upper(),
                'birthdate': newDateFmt,
                'birth_place': self.pBirthOfUser,
                'is_company': False
            }
        )

Can someone explain me what does it mean exactly and how do I use correctly ?