Updated an no longer working

I had the same problem after upgrading but after I changed my jquery enqueue code (in my functions.php file) to:

if (!is_admin()) add_action("wp_enqueue_scripts", "my_jquery_enqueue", 11);
	function my_jquery_enqueue() {
	   wp_deregister_script('jquery');
	   wp_register_script('jquery', "http" . ($_SERVER['SERVER_PORT'] == 443 ? "s" : "") . "://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js", false, null);
	   wp_enqueue_script('jquery');
	}

it worked!

I suppose the problem was that since my theme was loading an older version of jquery(1.4) it couldn’t work as the updated version runs on newer jquery

Hope that helps.