Index: lib/Doctrine/Hydrator/Graph.php
===================================================================
--- lib/Doctrine/Hydrator/Graph.php	(revision 7690)
+++ lib/Doctrine/Hydrator/Graph.php	(working copy)
@@ -252,8 +252,11 @@
                     $oneToOne = true;
                     if ( ! isset($nonemptyComponents[$dqlAlias]) && ! isset($prev[$parent][$relationAlias])) {
                         $prev[$parent][$relationAlias] = $this->getNullPointer();
-                    } else if ( ! isset($prev[$parent][$relationAlias])) {
-                        $element = $this->getElement($data, $componentName);
+                    } else {
+                        //is the element cached in the parent table identityMap?
+                        $element = isset($prev[$parent][$relationAlias])
+                                ? $prev[$parent][$relationAlias]
+                                : $this->getElement($data, $componentName);
 
 						// [FIX] Tickets #1205 and #1237
                         $event->set('data', $element);