Refs #39, document that aggregates do not work with taggit.

docs/api.txt

@@ -71,3 +71,12 @@ make use of the ``distinct()`` method on ``QuerySets``::
 
 
 You can also filter by the slug on tags.  If you're using a custom ``Tag``
 You can also filter by the slug on tags.  If you're using a custom ``Tag``
 model you can use this API to filter on any fields it has.
 model you can use this API to filter on any fields it has.
+
+Aggregation
+~~~~~~~~~~~
+
+Unfortunately, due to a
+`bug in Django <http://code.djangoproject.com/ticket/10870>`_, it is not
+currently possible to use aggregation in conjunction with ``taggit``.  This is
+a `documented interaction <http://docs.djangoproject.com/en/dev/ref/contrib/contenttypes/#generic-relations-and-aggregation>`_
+of generic relations (which ``taggit`` uses internally) and aggregates.

docs/changelog.txt

@@ -34,4 +34,3 @@ Unreleased.
    transaction with an ``IntegrityError``.
    transaction with an ``IntegrityError``.
  * Added Python 2.4 compatibility.
  * Added Python 2.4 compatibility.
  * Added Django 1.1 compatibility.
  * Added Django 1.1 compatibility.
-