diff --git a/lib/classes/databox/subdefsStructure.class.php b/lib/classes/databox/subdefsStructure.class.php
index d4248fa979..a47b8c6d8c 100644
--- a/lib/classes/databox/subdefsStructure.class.php
+++ b/lib/classes/databox/subdefsStructure.class.php
@@ -150,8 +150,8 @@ class databox_subdefsStructure implements IteratorAggregate
             . 'subdef[@name="' . $name . '"]'
         );
 
-        if ($nodes->length > 0) {
-            $node = $nodes->item(0);
+        for($i = 0; $i < $nodes->length; $i++) {
+            $node = $nodes->item($i);
             $parent = $node->parentNode;
             $parent->removeChild($node);
         }
diff --git a/tests/Alchemy/Phrasea/Controller/Admin/SubdefsTest.php b/tests/Alchemy/Phrasea/Controller/Admin/SubdefsTest.php
index 7b886d0b66..d7cda667b7 100644
--- a/tests/Alchemy/Phrasea/Controller/Admin/SubdefsTest.php
+++ b/tests/Alchemy/Phrasea/Controller/Admin/SubdefsTest.php
@@ -5,21 +5,24 @@ require_once __DIR__ . '/../../../../PhraseanetWebTestCaseAuthenticatedAbstract.
 class ControllerSubdefsTest extends \PhraseanetWebTestCaseAuthenticatedAbstract
 {
     protected $client;
+    protected $app;
+    protected $databox;
 
     public function createApplication()
     {
-        $app = require __DIR__ . '/../../../../../lib/Alchemy/Phrasea/Application/Admin.php';
-        
-        $app['debug'] = true;
-        unset($app['exception_handler']);
-        
-        return $app;
+        $this->app = require __DIR__ . '/../../../../../lib/Alchemy/Phrasea/Application/Admin.php';
+
+        $this->app['debug'] = true;
+        unset($this->app['exception_handler']);
+
+        return $this->app;
     }
 
     public function setUp()
     {
         parent::setUp();
         $this->client = $this->createClient();
+        $this->databox = array_shift($this->app['phraseanet.appbox']->get_databoxes());
     }
 
     /**
@@ -27,37 +30,38 @@ class ControllerSubdefsTest extends \PhraseanetWebTestCaseAuthenticatedAbstract
      */
     public function testRouteGetSubdef()
     {
-        $appbox = appbox::get_instance(\bootstrap::getCore());
-        $databox = array_shift($appbox->get_databoxes());
-        $this->client->request("GET", "/subdefs/" . $databox->get_sbas_id() . "/");
+        $this->client->request("GET", "/subdefs/" .  $this->databox->get_sbas_id() . "/");
         $this->assertTrue($this->client->getResponse()->isOk());
     }
 
+    public function getName()
+    {
+        return 'testname' . time() . mt_rand(10000, 99999);
+    }
+
     public function testPostRouteAddSubdef()
     {
-        $appbox = appbox::get_instance(\bootstrap::getCore());
-        $databox = array_shift($appbox->get_databoxes());
-        $this->client->request("POST", "/subdefs/" . $databox->get_sbas_id() . "/", array('add_subdef' => array(
+        $name = $this->getName();
+        $this->client->request("POST", "/subdefs/" .  $this->databox->get_sbas_id() . "/", array('add_subdef' => array(
                 'class'  => 'thumbnail',
-                'name'   => 'aname',
+                'name'   => $name,
                 'group'  => 'image'
             )));
         $this->assertTrue($this->client->getResponse()->isRedirect());
-        $subdefs = $databox->get_subdef_structure();
-        $subdefs->get_subdef("image", "aname");
-        $subdefs->delete_subdef('image', 'aname');
+        $subdefs =  $this->databox->get_subdef_structure();
+        $subdefs->get_subdef("image", $name);
+        $subdefs->delete_subdef('image', $name);
     }
 
     public function testPostRouteDeleteSubdef()
     {
-        $appbox = appbox::get_instance(\bootstrap::getCore());
-        $databox = array_shift($appbox->get_databoxes());
-        $subdefs = $databox->get_subdef_structure();
-        $subdefs->add_subdef("image", "name", "class");
-        $this->client->request("POST", "/subdefs/" . $databox->get_sbas_id() . "/", array('delete_subdef' => 'group_name'));
+        $subdefs =  $this->databox->get_subdef_structure();
+        $name = $this->getName();
+        $subdefs->add_subdef("image", $name, "thumbnail");
+        $this->client->request("POST", "/subdefs/" .  $this->databox->get_sbas_id() . "/", array('delete_subdef' => 'image_' . $name));
         $this->assertTrue($this->client->getResponse()->isRedirect());
         try {
-            $subdefs->get_subdef("image", "name");
+            $subdefs->get_subdef("image", $name);
             $this->fail("should raise an exception");
         } catch (\Exception $e) {
 
@@ -66,27 +70,27 @@ class ControllerSubdefsTest extends \PhraseanetWebTestCaseAuthenticatedAbstract
 
     public function testPostRouteAddSubdefWithNoParams()
     {
-        $appbox = appbox::get_instance(\bootstrap::getCore());
-        $databox = array_shift($appbox->get_databoxes());
-        $subdefs = $databox->get_subdef_structure();
-        $subdefs->add_subdef("image", "name", "class");
-        $this->client->request("POST", "/subdefs/" . $databox->get_sbas_id() . "/"
+        $subdefs =  $this->databox->get_subdef_structure();
+        $name = $this->getName();
+        $subdefs->add_subdef("image", $name, "thumbnail");
+        $this->client->request("POST", "/subdefs/" .  $this->databox->get_sbas_id() . "/"
             , array('subdefs' => array(
-                'image_name'
+                'image_' . $name
             )
-            , 'image_name_class'        => 'class'
-            , 'image_name_downloadable' => 0
-            , 'image_name_mediatype'    => 'image'
-            , 'image_name_image'        => array(
-                'size'       => 400
-                , 'resolution' => 83
-                , 'strip'      => 0
-                , 'quality'    => 90
+            , 'image_' . $name . '_class'        => 'thumbnail'
+            , 'image_' . $name . '_downloadable' => 0
+            , 'image_' . $name . '_mediatype'    => 'image'
+            , 'image_' . $name . '_image'        => array(
+                'size'       => 400,
+                'resolution' => 83,
+                'strip'      => 0,
+                'quality'    => 90,
             ))
         );
 
         $this->assertTrue($this->client->getResponse()->isRedirect());
-        $subdef = $subdefs->get_subdef("image", "name");
+        $subdefs = new databox_subdefsStructure( $this->databox);
+        $subdef = $subdefs->get_subdef("image", $name);
 
         /* @var $subdef \databox_subdef */
         $this->assertFalse($subdef->is_downloadable());
@@ -100,6 +104,6 @@ class ControllerSubdefsTest extends \PhraseanetWebTestCaseAuthenticatedAbstract
         $this->assertEquals(90, $options[\Alchemy\Phrasea\Media\Subdef\Image::OPTION_QUALITY]->getValue());
         $this->assertFalse($options[\Alchemy\Phrasea\Media\Subdef\Image::OPTION_STRIP]->getValue());
 
-        $subdefs->delete_subdef("image", "name");
+        $subdefs->delete_subdef("image", $name);
     }
 }