Index: dataobject_manager/code/DataObjectManager.php
===================================================================
--- dataobject_manager/code/DataObjectManager.php	(revision 340)
+++ dataobject_manager/code/DataObjectManager.php	(working copy)
@@ -486,8 +486,10 @@
 	
 	public function removePermission($perm)
 	{
-		if($key = array_search($perm,$this->permissions))
+		$key = array_search($perm,$this->permissions);
+		if($key !== false){
 			unset($this->permissions[$key]);
+		}
 	}
 	
 	public function NestedType()