mod/assign/locallib.php-patch

--- moodle/mod/assign/locallib.php  2012-08-16 20:06:14.000000000 -0400
+++ html/mod/assign/locallib.php    2012-09-19 11:23:10.000000000 -0400
@@ -1062,11 +1062,17 @@
             $sort = "a.$sort $dir";
         }

+        $currentgroup = groups_get_activity_group($this->get_course_module(), true);
+        $users = array_keys( $this->list_participants($currentgroup, true));
+        list($userwhere, $userparams) = $DB->get_in_or_equal($users, SQL_PARAMS_QM, 'user');
+        $where = 'u.id ' . $userwhere;
+
         return $DB->get_records_sql("SELECT a.*
                                        FROM {assign_submission} a, {user} u
                                       WHERE u.id = a.userid
                                             AND a.assignment = ?
-                                   ORDER BY $sort", array($this->get_instance()->id));
+                                            AND $where
+                                   ORDER BY $sort", array_merge(array($this->get_instance()->id), $userparams));

     }