--- original_views_groupby_handler_field_groupfields.inc	2009-04-02 06:56:32.000000000 +0200
+++ views_groupby_handler_field_groupfields.inc	2009-04-29 13:45:35.000000000 +0200
@@ -62,7 +62,8 @@ class views_groupby_handler_field_groupf
     );
     
     
-    $options_sql_func = array( 'count' => t('Count') );
+    $options_sql_func = array( 'count' => t('Count'),
+                               'sum' => t('Sum') );
     $form['views_groupby_sql_function'] = array(
       '#title' => t('SQL Aggregation Function'),
       '#type' => 'select',