Index: node.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/node/node.module,v
retrieving revision 1.947
diff -u -r1.947 node.module
--- node.module	3 Feb 2008 19:41:47 -0000	1.947
+++ node.module	12 Feb 2008 23:13:57 -0000
@@ -1032,7 +1032,7 @@
   // First we'll overwrite the existing node teaser and body with
   // the filtered copies! Then, we'll stick those into the content
   // array and set the read more flag if appropriate.
-  $node->readmore = (strlen($node->teaser) < strlen($node->body));
+  $node->readmore = $node->teaser !== $node->body;
 
   if ($teaser == FALSE) {
     $node->body = check_markup($node->body, $node->format, FALSE);