--- cck_teaser_field.module	2008-01-14 18:11:57.000000000 +0100
+++ cck_teaser_field.module	2008-01-14 18:12:08.000000000 +0100
@@ -31,8 +31,10 @@ function cck_teaser_field_nodeapi(&$node
   if ($op == 'alter' && $field = variable_get('teaser_field_'. $node->type, 0)) {
     if (isset($node->content[$field]) && !empty($node->content[$field]['#value'])) {
       $node->teaser = $node->content[$field]['#value'];
-      $node->readmore = TRUE;
     }
   }
+  elseif ($op == 'view' && $field = variable_get('teaser_field_'. $node->type, 0)) {
+    $node->readmore = true;
+  }
 }