[fix] Unsaved object

coin/configuration/models.py

@@ -68,12 +68,13 @@ class Configuration(PolymorphicModel):
 
     def save(self, **kwargs):
         self.clean()
-        os = self.offersubscription
+        config = super(Configuration, self).save(**kwargs)
+        os = config.offersubscription
         for offer_ip_pool in os.offer.offerippool_set.order_by('-to_assign'):
             IPSubnet.objects.create(
-                            configuration=self,
+                            configuration=config,
                             ip_pool=offer_ip_pool.ip_pool)
-        return super(Configuration, self).save(**kwargs)
+        return config
 
     class Meta:
         verbose_name = 'configuration'