Index: excerpt.module
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/excerpt/excerpt.module,v
retrieving revision 1.12
diff -u -r1.12 excerpt.module
--- excerpt.module	27 Mar 2008 11:54:15 -0000	1.12
+++ excerpt.module	30 Oct 2008 14:45:04 -0000
@@ -61,10 +61,11 @@
     );
   }
   else if (isset($form['type']) && $form['type']['#value'] .'_node_form' == $form_id && variable_get('excerpt_'. $form['type']['#value'], 1)) {
+    $form['#node']->teaser == node_teaser($form['#node']->body) ? $default = '' : $default = $form['#node']->teaser;
     $form['teaser'] = array(
       '#type' => 'textarea',
       '#title' => t('Teaser'),
-      '#default_value' => $form['#node']->teaser,
+      '#default_value' => $default,
       '#cols' => 60,
       '#rows' => 6,
       '#weight' => variable_get('excerpt_wt_'. $form['type']['#value'], 0),