Index: includes/tablesort.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/tablesort.inc,v
retrieving revision 1.38.2.1
diff -u -p -r1.38.2.1 tablesort.inc
--- includes/tablesort.inc	18 Jul 2006 11:40:56 -0000	1.38.2.1
+++ includes/tablesort.inc	30 Nov 2006 13:00:23 -0000
@@ -66,7 +66,12 @@ function tablesort_header($cell, $header
     $title = t('sort by %s', array('%s' => $cell['data']));
     if ($cell['data'] == $ts['name']) {
       $ts['sort'] = (($ts['sort'] == 'asc') ? 'desc' : 'asc');
-      $cell['class'] = 'active';
+      if (isset($cell['class'])) {
+        $cell['class'] .= ' active';
+      }
+      else {
+        $cell['class'] = 'active';
+      }
       $image = theme('tablesort_indicator', $ts['sort']);
     }
     else {