This one's already accepted, but if there are any other dummies out there (like me) that didn't immediately get it from the presently accepted answer, here's a bit more detail.
The model class referenced by the ForeignKey
needs to have a __unicode__
method within it, like here:
class Category(models.Model):
name = models.CharField(max_length=50)
def __unicode__(self):
return self.name
That made the difference for me, and should apply to the above scenario. This works on Django 1.0.2.