I also have qTranslate but the above code doesn’t work for me.
The only hack that helped in my case is to insert the new method in class Visual_Form_Builder (in visual-form-builder.php file):
public function localize_vfb() {
$plugin_dir = basename(dirname(__FILE__));
load_plugin_textdomain( 'visual-form-builder', false, $plugin_dir. '/languages/' );
}
and call it in function __construct():
add_action('plugins_loaded', array( &$this, 'localize_vfb' ));
My attempts to resolve this through functions.php file didn’t succeed.