Index: ./modules/node/node.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/node/node.module,v
retrieving revision 1.806
diff -u -p -r1.806 node.module
--- ./modules/node/node.module	30 Apr 2007 17:03:26 -0000	1.806
+++ ./modules/node/node.module	7 May 2007 01:09:04 -0000
@@ -764,7 +764,7 @@ function node_prepare($node, $teaser = F
   // 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 = $teaser && (strlen($node->teaser)) && (strlen($node->teaser) < strlen($node->body));
 
   if ($teaser == FALSE) {
     $node->body = check_markup($node->body, $node->format, FALSE);