--- scheduler.module.orig	2008-04-25 11:37:56.000000000 +0200
+++ scheduler.module	2008-04-25 11:39:34.000000000 +0200
@@ -150,7 +150,7 @@ function scheduler_nodeapi(&$node, $op, 
 
   // Run $op == load for any user.
   if ($op == 'load') {
-    if (isset($node->nid) && $node->nid) {
+    if (isset($node->nid) && $node->nid && variable_get('scheduler_'. $node->type, 0) == 1) {
       $result = db_query('SELECT * FROM {scheduler} WHERE nid = %d', $node->nid);
       if ($result) {
         $row = db_fetch_array($result);