Index: misc/teaser.js
===================================================================
RCS file: /cvs/drupal/drupal/misc/teaser.js,v
retrieving revision 1.10
diff -u -p -r1.10 teaser.js
--- misc/teaser.js	13 Nov 2007 14:04:08 -0000	1.10
+++ misc/teaser.js	18 Dec 2007 15:49:22 -0000
@@ -30,12 +30,13 @@ Drupal.behaviors.teaser = function(conte
       if (teaser.val()) {
         body.val(trim(teaser.val()) +'\r\n\r\n'+ trim(body.val()));
       }
-      // Hide and disable teaser
+      // Empty, hide and disable teaser
+      teaser[0].value = '';
       $(teaser).attr('disabled', 'disabled');
       $(teaser).parent().slideUp('fast');
       // Change label
       $(this).val(Drupal.t('Split summary at cursor'));
-      // Show separate teaser checkbox
+      // Hide separate teaser checkbox
       $(checkbox).hide();
     }