JavaScript PushState / PopState disables other scripts

I have this code on my site js / pushstate.js:

$(document).ready(function() {
var nav, conteudo, fetchAndInsert;

//nav = $('div#navbar');
nav = $('.menu');
conteudo = $('#conteudo');

fetchAndInsert = function(href) {
    $.ajax({
        url: 'http://somdomato.com/cont/' + href.split('/').pop(),
        method: 'GET',
        cache: false,
        success: function(data) {
            conteudo.html(data);
        }
    });
};

$(window).on('popstate', function() {
    fetchAndInsert(location.pathname);
});

nav.find('a').on('click', function(e) {
    var href = $(this).attr('href');
    history.pushState(null, null, href);
    fetchAndInsert(href);
    e.preventDefault();
});
});

/index.php:

<?php require 'inc/cabecalho.inc.php'; ?>

<div id="conteudo">
    <?php require 'cont/index.php'; ?>
</div>

<?php require 'inc/rodape.inc.php'; ?>

The script works fine and pages load without the player to stop playing the song and the address changes as expected.

The problem is that when I switch from page to page all other scripts stop working.

The url is link Anyone have an idea of what might be happening?

Thank you.