Example to illustrate a problem I'm having with multi-table inheritance for user profiles in django and Userena

forms.py

# This is the form to sign up a Spam Type Person

from django import forms
from userena.forms import SignupFormTos
from . models import CommonProfile, SpamProfile

class SpamSignupForm(SignupFormTos):
    """signup a Spam Person"""
    common_field = forms.CharField(label='what is your quest')
    spam_field = forms.CharField(label='what kind of spam are you')
    
    def clean(self):
        cleaned_data = super(SpamSignupForm,self).clean()
        #do stuf, same idea for clean_<field>
        return cleaned_data

    def save(self):
        """Save the SpamProfile"""
        user = super(SpamSignupForm,self).save()
        common_profile = user.get_profile()
        spam_profile = SpamProfile(commonprofile_ptr=common_profile)
        spam_profile.spam_field = self.cleaned_data['spam_field']
        spam_profile.save()
        return spam_profile

models.py

# This is an example of how i've attempted to get 
# multiple user profiles working with Userena

from django.contrib.auth.models import User
from django.db import models
from userena.models import UserenaLanguageBaseProfile


class CommonProfile(UserenaLanguageBaseProfile):
    """Common fields for 2 user profiles: Spam and Eggs"""
    user = models.OneToOneField(User)
    common_field = models.CharField(max_length=100)

    @property
    def is_spam(self):
        """Find out if this is a Spam user"""
        try:
            self.spamprofile
            return True
        except SpamProfile.DoesNotExist:
            return False

    def get_real_type(self):
        """return the real model"""
        if self.is_spam:
            return self.spamprofile
        else:
            return self.eggsprofile

class SpamProfile(CommonProfile):
    spam_field = models.CharField(max_length=20)

class EggsField(CommonProfile):
    eggs_field = models.SmallIntegerField()

I've seen you asked this on SO: http://stackoverflow.com/q/10778980/1191416
Could you please tell us if you have found a solution? If positive it would be very kind of you to share it.
I'm also struggling with it!