Index: corresponding_node_references.module
===================================================================
--- corresponding_node_references.module	(revision 3038)
+++ corresponding_node_references.module	(revision 3039)
@@ -149,9 +149,14 @@
  */
 function corresponding_node_references_nodeapi(&$node, $op, $a3 = NULL, $a4 = NULL) {
 
-  switch ($op) {
+  switch ($op) {     
+    case 'presave':
+      // presave when node has nid already is like before_update.
+      if ($node->nid) {
+        corresponding_node_references_process_node('update', $node);
+      }
+      break;
     case 'insert':
-    case 'update':
     case 'delete':
       corresponding_node_references_process_node($op, $node);
       break;