maybe someone can explain me meaning of this error:

File "/opt/odoo/openerp/api.py", line 715, in __new__

self.registry = RegistryManager.get(cr.dbname)

AttributeError: 'crm.lead' object has no attribute 'dbname'

from my module i call other function from inherited class

my code

class crm_lead(models.Model):

_inherit = 'crm.lead'

def custom_create_contact(self, cr, uid, ids, context=None):

res = self.handle_partner_assignation(self, cr, uid, ids)

return res

I am calling this function with button from lead form.

Thanks!