Index: includes/form.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/form.inc,v
retrieving revision 1.487
diff -u -p -r1.487 form.inc
--- includes/form.inc	30 Aug 2010 17:07:49 -0000	1.487
+++ includes/form.inc	30 Aug 2010 17:47:39 -0000
@@ -2788,12 +2810,13 @@ function theme_tableselect($variables) {
     // Add an empty header or a "Select all" checkbox to provide room for the
     // checkboxes/radios in the first table column.
     if ($element['#js_select']) {
-      // Add a "Select all" checkbox when checkboxes are displayed.
+      // Add a "Select all" checkbox.
       drupal_add_js('misc/tableselect.js');
       array_unshift($header, array('class' => array('select-all')));
     }
     else {
-      // Add an empty header when radio buttons are displayed.
+      // Add an empty header when radio buttons are displayed or a "Select all"
+      // checkbox is not desired.
       array_unshift($header, '');
     }
   }