title: django modeltranslation removes data
body: <p>i am having weird trouble translating <a href="https://github.com/mvpdev/django-eav" rel="nofollow">django-eav</a> fields with <a href="https://github.com/deschler/django-modeltranslation" rel="nofollow">model translation</a>. I want to translate EnumValue field <code>value</code>. Code in translations.py Here's </p>
  
  <pre><code>class EnumValueTranslationOptions(TranslationOptions):
      fields = ('value', )
  
  translator.register(EnumValue, EnumValueTranslationOptions)
  </code></pre>
  
  <p>That <code>value</code> is in eav/models.py:</p>
  
  <pre><code>class EnumValue(models.Model):
       value = models.CharField(_(u"value"), db_index=True,
                               unique=True, max_length=50)
       icon = models.ImageField(upload_to='enumvalue_icons/',blank=True,null=True, max_length=300, verbose_name=_('Icon'))
  </code></pre>
  
  <p>Problem is, i already have a lot of EnumValues in database. When i write this translation code and do migrations, old values just disappear. Objects are still there with other fields like <code>icon</code>, but values are empty. If i try add value, that existed before, it says: <strong>value already exists</strong>. If i comment translation code and do migrations, old values are back in place. Why is this happening?</p>