Index: views/handlers/views_handler_filter_string.inc
===================================================================
--- views/handlers/views_handler_filter_string.inc	(revision )
+++ views/handlers/views_handler_filter_string.inc	(revision )
@@ -7,12 +7,12 @@
 class views_handler_filter_string extends views_handler_filter {
   // exposed filter options
   var $no_single = TRUE;
-  var $no_optional = TRUE;
+  var $no_optional = FALSE;
 
   function option_definition() {
     $options = parent::option_definition();
 
-    $options['expose']['contains']['optional'] = array('default' => FALSE);
+    $options['expose']['contains']['optional'] = array('default' => TRUE);
     $options['case'] = array('default' => TRUE);
 
     return $options;