Index: django/contrib/comments/templatetags/comments.py
===================================================================
--- django/contrib/comments/templatetags/comments.py	(revision 5178)
+++ django/contrib/comments/templatetags/comments.py	(working copy)
@@ -111,9 +111,9 @@
             'site__id__exact': settings.SITE_ID,
         }
         kwargs.update(self.extra_kwargs)
+        comment_list = get_list_function(**kwargs).order_by(self.ordering + 'submit_date').select_related()
         if not self.free and settings.COMMENTS_BANNED_USERS_GROUP:
-            kwargs['select'] = {'is_hidden': 'user_id IN (SELECT user_id FROM auth_user_groups WHERE group_id = %s)' % settings.COMMENTS_BANNED_USERS_GROUP}
-        comment_list = get_list_function(**kwargs).order_by(self.ordering + 'submit_date').select_related()
+            comment_list = comment_list.extra(select={'is_hidden': 'user_id IN (SELECT user_id FROM auth_user_groups WHERE group_id = %s)' % settings.COMMENTS_BANNED_USERS_GROUP})
 
         if not self.free:
             if 'user' in context and context['user'].is_authenticated():
Index: django/contrib/comments/models.py
===================================================================
--- django/contrib/comments/models.py	(revision 5178)
+++ django/contrib/comments/models.py	(working copy)
@@ -106,7 +106,10 @@
         return "%s: %s..." % (self.user.username, self.comment[:100])
 
     def get_absolute_url(self):
-        return self.get_content_object().get_absolute_url() + "#c" + str(self.id)
+        try:
+            return self.get_content_object().get_absolute_url() + "#c" + str(self.id)
+        except AttributeError:
+            return ""
 
     def get_crossdomain_url(self):
         return "/r/%d/%d/" % (self.content_type_id, self.object_id)
@@ -191,7 +194,10 @@
         return "%s: %s..." % (self.person_name, self.comment[:100])
 
     def get_absolute_url(self):
-        return self.get_content_object().get_absolute_url() + "#c" + str(self.id)
+        try:
+            return self.get_content_object().get_absolute_url() + "#c" + str(self.id)
+        except AttributeError:
+            return ""
 
     def get_content_object(self):
         """
Index: django/contrib/comments/views/comments.py
===================================================================
--- django/contrib/comments/views/comments.py	(revision 5178)
+++ django/contrib/comments/views/comments.py	(working copy)
@@ -112,7 +112,7 @@
                 'This comment was posted by a user who has posted fewer than %(count)s comments:\n\n%(text)s', settings.COMMENTS_FIRST_FEW) % \
                 {'count': settings.COMMENTS_FIRST_FEW, 'text': c.get_as_text()}
             mail_managers("Comment posted by rookie user", message)
-        if settings.COMMENTS_SKETCHY_USERS_GROUP and settings.COMMENTS_SKETCHY_USERS_GROUP in [g.id for g in self.user_cache.get_group_list()]:
+        if settings.COMMENTS_SKETCHY_USERS_GROUP and settings.COMMENTS_SKETCHY_USERS_GROUP in [g.id for g in self.user_cache.groups.all()]:
             message = _('This comment was posted by a sketchy user:\n\n%(text)s') % {'text': c.get_as_text()}
             mail_managers("Comment posted by sketchy user (%s)" % self.user_cache.username, c.get_as_text())
         return c