diff --git a/lib/Doctrine/ORM/PersistentCollection.php b/lib/Doctrine/ORM/PersistentCollection.php
index b56d0930b..fc2a00ba1 100644
--- a/lib/Doctrine/ORM/PersistentCollection.php
+++ b/lib/Doctrine/ORM/PersistentCollection.php
@@ -404,22 +404,12 @@ final class PersistentCollection implements Collection
      */
     public function contains($element)
     {
-        /* DRAFT
-        if ($this->initialized) {
-            return $this->coll->contains($element);
-        } else {
-            if ($element is MANAGED) {
-                if ($this->coll->contains($element)) {
-                    return true;
-                }
-                $exists = check db for existence;
-                if ($exists) {
-                    $this->coll->add($element);
-                }
-                return $exists;
-            }
-            return false;
-        }*/
+        if (!$this->initialized && $this->association['fetch'] == Mapping\ClassMetadataInfo::FETCH_EXTRALAZY) {
+            return $this->coll->contains($element) ||
+                   $this->em->getUnitOfWork()
+                            ->getCollectionPersister($this->association)
+                            ->contains($this, $element);
+        }
         
         $this->initialize();
         return $this->coll->contains($element);
@@ -481,7 +471,7 @@ final class PersistentCollection implements Collection
             if (!isset($this->doctrineCollectionCount)) {
                 $this->doctrineCollectionCount = $this->em->getUnitOfWork()
                                 ->getCollectionPersister($this->association)
-                                ->count($this) + count ($this->coll->toArray());
+                                ->count($this) + $this->coll->count();
             }
             return $this->doctrineCollectionCount;
         }
diff --git a/lib/Doctrine/ORM/Persisters/AbstractCollectionPersister.php b/lib/Doctrine/ORM/Persisters/AbstractCollectionPersister.php
index 1847c7136..189809697 100644
--- a/lib/Doctrine/ORM/Persisters/AbstractCollectionPersister.php
+++ b/lib/Doctrine/ORM/Persisters/AbstractCollectionPersister.php
@@ -135,12 +135,12 @@ abstract class AbstractCollectionPersister
         throw new \BadMethodCallException("Slicing elements is not supported by this CollectionPersister.");
     }
 
-    public function contains(PersistentCollection $coll, $key)
+    public function contains(PersistentCollection $coll, $element)
     {
         throw new \BadMethodCallException("Checking for existance of an element is not supported by this CollectionPersister.");
     }
 
-    public function containsKey(PersistentCollection $coll, $element)
+    public function containsKey(PersistentCollection $coll, $key)
     {
         throw new \BadMethodCallException("Checking for existance of a key is not supported by this CollectionPersister.");
     }
diff --git a/lib/Doctrine/ORM/Persisters/BasicEntityPersister.php b/lib/Doctrine/ORM/Persisters/BasicEntityPersister.php
index 9d4974eac..0eb46edcb 100644
--- a/lib/Doctrine/ORM/Persisters/BasicEntityPersister.php
+++ b/lib/Doctrine/ORM/Persisters/BasicEntityPersister.php
@@ -1326,21 +1326,17 @@ class BasicEntityPersister
      * @param object $entity
      * @return boolean TRUE if the entity exists in the database, FALSE otherwise.
      */
-    public function exists($entity)
+    public function exists($entity, array $extraConditions = array())
     {
         $criteria = $this->_class->getIdentifierValues($entity);
+        if ($extraConditions) {
+            $criteria = array_merge($criteria, $extraConditions);
+        }
+
         $sql = 'SELECT 1 FROM ' . $this->_class->getQuotedTableName($this->_platform)
                 . ' ' . $this->_getSQLTableAlias($this->_class->name)
                 . ' WHERE ' . $this->_getSelectConditionSQL($criteria);
 
         return (bool) $this->_conn->fetchColumn($sql, array_values($criteria));
     }
-
-    //TODO
-    /*protected function _getOneToOneEagerFetchSQL()
-    {
-        
-    }*/
-
-    #public function countCollection
 }
diff --git a/lib/Doctrine/ORM/Persisters/ManyToManyPersister.php b/lib/Doctrine/ORM/Persisters/ManyToManyPersister.php
index 65afe23f0..9e3dc93b5 100644
--- a/lib/Doctrine/ORM/Persisters/ManyToManyPersister.php
+++ b/lib/Doctrine/ORM/Persisters/ManyToManyPersister.php
@@ -21,7 +21,8 @@
 
 namespace Doctrine\ORM\Persisters;
 
-use Doctrine\ORM\PersistentCollection;
+use Doctrine\ORM\PersistentCollection,
+    Doctrine\ORM\UnitOfWork;
 
 /**
  * Persister for many-to-many collections.
@@ -230,4 +231,53 @@ class ManyToManyPersister extends AbstractCollectionPersister
                   ->getEntityPersister($mapping['targetEntity'])
                   ->getManyToManyCollection($mapping, $coll->getOwner(), $offset, $length);
     }
+
+    /**
+     * @param PersistentCollection $coll
+     * @param object $element
+     */
+    public function contains(PersistentCollection $coll, $element)
+    {
+        $uow = $this->_em->getUnitOfWork();
+
+        // shortcut for new entities
+        if ($uow->getEntityState($element, UnitOfWork::STATE_NEW) == UnitOfWork::STATE_NEW) {
+            return false;
+        }
+
+        $params = array();
+        $mapping = $coll->getMapping();
+        $sourceClass = $this->_em->getClassMetadata($mapping['sourceEntity']);
+        $elementClass = $this->_em->getClassMetadata($mapping['targetEntity']);
+        $sourceId = $uow->getEntityIdentifier($coll->getOwner());
+        $elementId = $uow->getEntityIdentifier($element);
+
+        if ($mapping['isOwningSide']) {
+            $joinTable = $mapping['joinTable'];
+        } else {
+            $joinTable = $elementClass->associationMappings[$mapping['mappedBy']]['joinTable'];
+        }
+
+        $whereClause = '';
+        foreach ($mapping['joinTableColumns'] as $joinTableColumn) {
+            if (isset($mapping['relationToTargetKeyColumns'][$joinTableColumn])) {
+                if ($whereClause !== '') {
+                    $whereClause .= ' AND ';
+                }
+                $whereClause .= "$joinTableColumn = ?";
+
+                $params[] = $elementId[$sourceClass->fieldNames[$mapping['relationToTargetKeyColumns'][$joinTableColumn]]];
+            } else if (isset($mapping['relationToSourceKeyColumns'][$joinTableColumn])) {
+                if ($whereClause !== '') {
+                    $whereClause .= ' AND ';
+                }
+                $whereClause .= "$joinTableColumn = ?";
+
+                $params[] = $sourceId[$sourceClass->fieldNames[$mapping['relationToSourceKeyColumns'][$joinTableColumn]]];
+            }
+        }
+        $sql = 'SELECT 1 FROM ' . $joinTable['name'] . ' WHERE ' . $whereClause;
+
+        return (bool)$this->_conn->fetchColumn($sql, $params);
+    }
 }
\ No newline at end of file
diff --git a/lib/Doctrine/ORM/Persisters/OneToManyPersister.php b/lib/Doctrine/ORM/Persisters/OneToManyPersister.php
index d60cc980f..4e17cb973 100644
--- a/lib/Doctrine/ORM/Persisters/OneToManyPersister.php
+++ b/lib/Doctrine/ORM/Persisters/OneToManyPersister.php
@@ -21,7 +21,8 @@
 
 namespace Doctrine\ORM\Persisters;
 
-use Doctrine\ORM\PersistentCollection;
+use Doctrine\ORM\PersistentCollection,
+    Doctrine\ORM\UnitOfWork;
 
 /**
  * Persister for one-to-many collections.
@@ -153,4 +154,26 @@ class OneToManyPersister extends AbstractCollectionPersister
                   ->getEntityPersister($mapping['targetEntity'])
                   ->getOneToManyCollection($mapping, $coll->getOwner(), $offset, $length);
     }
+
+    /**
+     * @param PersistentCollection $coll
+     * @param object $element
+     */
+    public function contains(PersistentCollection $coll, $element)
+    {
+        $mapping = $coll->getMapping();
+        $uow = $this->_em->getUnitOfWork();
+        
+        // shortcut for new entities
+        if ($uow->getEntityState($element, UnitOfWork::STATE_NEW) == UnitOfWork::STATE_NEW) {
+            return false;
+        }
+
+        // only works with single id identifier entities. Will throw an exception in Entity Persisters
+        // if that is not the case for the 'mappedBy' field.
+        $id = current( $uow->getEntityIdentifier($coll->getOwner()) );
+
+        return $uow->getEntityPersister($mapping['targetEntity'])
+                   ->exists($element, array($mapping['mappedBy'] => $id));
+    }
 }
\ No newline at end of file
diff --git a/tests/Doctrine/Tests/ORM/Functional/ExtraLazyCollectionTest.php b/tests/Doctrine/Tests/ORM/Functional/ExtraLazyCollectionTest.php
index fbd6451ac..c4de77eac 100644
--- a/tests/Doctrine/Tests/ORM/Functional/ExtraLazyCollectionTest.php
+++ b/tests/Doctrine/Tests/ORM/Functional/ExtraLazyCollectionTest.php
@@ -15,6 +15,7 @@ class ExtraLazyCollectionTest extends \Doctrine\Tests\OrmFunctionalTestCase
 {
     private $userId;
     private $groupId;
+    private $articleId;
 
     public function setUp()
     {
@@ -215,6 +216,70 @@ class ExtraLazyCollectionTest extends \Doctrine\Tests\OrmFunctionalTestCase
         $this->assertEquals($queryCount + 2, $this->getCurrentQueryCount());
     }
 
+    /**
+     * @group DDC-546
+     */
+    public function testContainsOneToMany()
+    {
+        $user = $this->_em->find('Doctrine\Tests\Models\CMS\CmsUser', $this->userId);
+        $this->assertFalse($user->articles->isInitialized(), "Pre-Condition: Collection is not initialized.");
+
+        $article = $this->_em->find('Doctrine\Tests\Models\CMS\CmsArticle', $this->articleId);
+        
+        $queryCount = $this->getCurrentQueryCount();
+        $this->assertTrue($user->articles->contains($article));
+        $this->assertFalse($user->articles->isInitialized(), "Post-Condition: Collection is not initialized.");
+        $this->assertEquals($queryCount + 1, $this->getCurrentQueryCount());
+
+        $article = new \Doctrine\Tests\Models\CMS\CmsArticle();
+        $article->topic = "Testnew";
+        $article->text = "blub";
+
+        $queryCount = $this->getCurrentQueryCount();
+        $this->assertFalse($user->articles->contains($article));
+        $this->assertEquals($queryCount, $this->getCurrentQueryCount(), "Checking for contains of new entity should cause no query to be executed.");
+
+        $this->_em->persist($article);
+        $this->_em->flush();
+
+        $queryCount = $this->getCurrentQueryCount();
+        $this->assertFalse($user->articles->contains($article));
+        $this->assertEquals($queryCount+1, $this->getCurrentQueryCount(), "Checking for contains of managed entity should cause one query to be executed.");
+        $this->assertFalse($user->articles->isInitialized(), "Post-Condition: Collection is not initialized.");
+    }
+
+    /**
+     * @group DDC-546
+     */
+    public function testContainsManyToMany()
+    {
+        $user = $this->_em->find('Doctrine\Tests\Models\CMS\CmsUser', $this->userId);
+        $this->assertFalse($user->groups->isInitialized(), "Pre-Condition: Collection is not initialized.");
+
+        $group = $this->_em->find('Doctrine\Tests\Models\CMS\CmsGroup', $this->groupId);
+
+        $queryCount = $this->getCurrentQueryCount();
+        $this->assertTrue($user->groups->contains($group));
+        $this->assertEquals($queryCount+1, $this->getCurrentQueryCount(), "Checking for contains of managed entity should cause one query to be executed.");
+        $this->assertFalse($user->groups->isInitialized(), "Post-Condition: Collection is not initialized.");
+
+        $group = new \Doctrine\Tests\Models\CMS\CmsGroup();
+        $group->name = "A New group!";
+
+        $queryCount = $this->getCurrentQueryCount();
+        $this->assertFalse($user->groups->contains($group));
+        $this->assertEquals($queryCount, $this->getCurrentQueryCount(), "Checking for contains of new entity should cause no query to be executed.");
+        $this->assertFalse($user->groups->isInitialized(), "Post-Condition: Collection is not initialized.");
+
+        $this->_em->persist($group);
+        $this->_em->flush();
+
+        $queryCount = $this->getCurrentQueryCount();
+        $this->assertFalse($user->groups->contains($group));
+        $this->assertEquals($queryCount+1, $this->getCurrentQueryCount(), "Checking for contains of managed entity should cause one query to be executed.");
+        $this->assertFalse($user->groups->isInitialized(), "Post-Condition: Collection is not initialized.");
+    }
+
     private function loadFixture()
     {
         $user1 = new \Doctrine\Tests\Models\CMS\CmsUser();
@@ -278,7 +343,8 @@ class ExtraLazyCollectionTest extends \Doctrine\Tests\OrmFunctionalTestCase
         
         $this->_em->flush();
         $this->_em->clear();
-        
+
+        $this->articleId = $article1->id;
         $this->userId = $user1->getId();
         $this->groupId = $group1->id;
     }