diff --git a/classes/db_reg.php b/classes/db_reg.php
index c055563..1e1b4e4 100644
--- a/classes/db_reg.php
+++ b/classes/db_reg.php
@@ -62,7 +62,7 @@ class DB_Reg {
 	 */
 	public function __destruct()
 	{
-		unset(self::$instance);
+		self::$instance = NULL;
 	}
 
 	// --------------------------------------------------------------------------
diff --git a/tests/db_files/FB_TEST_DB.FDB b/tests/db_files/FB_TEST_DB.FDB
index 607f1a4..4422433 100755
Binary files a/tests/db_files/FB_TEST_DB.FDB and b/tests/db_files/FB_TEST_DB.FDB differ