diff --git a/lib/Doctrine/ORM/Id/AssignedGenerator.php b/lib/Doctrine/ORM/Id/AssignedGenerator.php
index 63c6e5418..05c3790af 100644
--- a/lib/Doctrine/ORM/Id/AssignedGenerator.php
+++ b/lib/Doctrine/ORM/Id/AssignedGenerator.php
@@ -49,7 +49,7 @@ class AssignedGenerator extends AbstractIdGenerator
             foreach ($idFields as $idField) {
                 $value = $class->reflFields[$idField]->getValue($entity);
                 if (isset($value)) {
-                    if (is_object($value)) {
+                    if (isset($class->associationMappings[$idField])) {
                         if (!$em->getUnitOfWork()->isInIdentityMap($value)) {
                             throw ORMException::entityMissingForeignAssignedId($entity, $value);
                         }
@@ -67,7 +67,7 @@ class AssignedGenerator extends AbstractIdGenerator
             $idField = $class->identifier[0];
             $value = $class->reflFields[$idField]->getValue($entity);
             if (isset($value)) {
-                if (is_object($value)) {
+                if (isset($class->associationMappings[$idField])) {
                     if (!$em->getUnitOfWork()->isInIdentityMap($value)) {
                         throw ORMException::entityMissingForeignAssignedId($entity, $value);
                     }
diff --git a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1209Test.php b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1209Test.php
index 8ff5e52a5..472978bc2 100644
--- a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1209Test.php
+++ b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1209Test.php
@@ -93,9 +93,9 @@ class DDC1209_2
     public function __construct(DDC1209_1 $future1)
     {
         $this->future1 = $future1;
-        $this->starting_datetime = new \DateTime();
-        $this->during_datetime = new \DateTime();
-        $this->ending_datetime = new \DateTime();
+        $this->starting_datetime = new DateTime2();
+        $this->during_datetime = new DateTime2();
+        $this->ending_datetime = new DateTime2();
     }
 }
 
@@ -120,6 +120,6 @@ class DateTime2 extends \DateTime
 {
     public function __toString()
     {
-        return $this->form('Y');
+        return $this->format('Y');
     }
 }
\ No newline at end of file