diff -r e891c6dcf1e0 tests/regressiontests/model_forms_regress/models.py
--- a/tests/regressiontests/model_forms_regress/models.py	Sun Jan 10 13:51:13 2010 -0300
+++ b/tests/regressiontests/model_forms_regress/models.py	Sun Jan 10 14:18:13 2010 -0300
@@ -37,3 +37,13 @@
 
 class CustomFF(models.Model):
     f = CustomFileField(upload_to='unused', blank=True)
+
+class Edition(models.Model):
+    author = models.ForeignKey(Person)
+    publication = models.ForeignKey(Publication)
+    edition = models.IntegerField()
+    isbn = models.CharField(max_length=13, unique=True)
+
+    class Meta:
+        unique_together = (('author', 'publication'), ('publication', 'edition'),)
+
diff -r e891c6dcf1e0 tests/regressiontests/model_forms_regress/tests.py
--- a/tests/regressiontests/model_forms_regress/tests.py	Sun Jan 10 13:51:13 2010 -0300
+++ b/tests/regressiontests/model_forms_regress/tests.py	Sun Jan 10 14:18:13 2010 -0300
@@ -6,7 +6,7 @@
 from django.conf import settings
 from django.test import TestCase
 
-from models import Person, Triple, FilePathModel, Article, Publication, CustomFF
+from models import Person, Triple, FilePathModel, Article, Publication, CustomFF, Edition
 
 class ModelMultipleChoiceFieldTests(TestCase):
 
@@ -113,3 +113,32 @@
             date_published=date(1991, 8, 22))
         f = Form()
         self.assertEqual(len(f.fields["publications"].choices), 1)
+
+class EditionForm(forms.ModelForm):
+    author = forms.ModelChoiceField(queryset=Person.objects.all())
+    publication = forms.ModelChoiceField(queryset=Publication.objects.all())
+    edition = forms.IntegerField()
+    isbn = forms.CharField(max_length=13)
+
+    class Meta:
+        model = Edition
+
+class UniqueErrorsTests(TestCase):
+
+    def setUp(self):
+        self.author1 = Person.objects.create(name=u'Author #1')
+        self.author2 = Person.objects.create(name=u'Author #2')
+        self.pub1 = Publication.objects.create(title='Pub #1', date_published=date(2000, 10, 31))
+        self.pub2 = Publication.objects.create(title='Pub #2', date_published=date(2004, 1, 5))
+        form = EditionForm(data={'author': self.author1.pk, 'publication': self.pub1.pk, 'edition': 1, 'isbn': '9783161484100'})
+        form.save()
+
+    def test_unique_error_message(self):
+        form = EditionForm(data={'author': self.author1.pk, 'publication': self.pub2.pk, 'edition': 1, 'isbn': '9783161484100'})
+        self.assertEquals(form.errors, {'isbn': [u'Edition with this Isbn already exists.']})
+
+    def test_unique_together_error_message(self):
+        form = EditionForm(data={'author': self.author1.pk, 'publication': self.pub1.pk, 'edition': 2, 'isbn': '9783161489999'})
+        self.assertEquals(form.errors, {'__all__': [u'Edition with this Author and Publication already exists.']})
+        form = EditionForm(data={'author': self.author2.pk, 'publication': self.pub1.pk, 'edition': 1, 'isbn': '9783161487777'})
+        self.assertEquals(form.errors, {'__all__': [u'Edition with this Publication and Edition already exists.']})