Saving twice causes model to become non-unique.

[JoelAlexander]

Given a redisco model:

class User(models.Model):
    name = models.Attribute(required=True, unique=True)
    password = models.Attribute()

the following sequence fails:

u = User(name='foo')
u.password = 'secret'
u.save()
u.save()

Now, maybe this is reasonable, but the big problem is the return value from the second save call is:

[('name', 'not unique')]

which is extremely misleading.