Bootstrap popover works with html but not requested webpage

I am trying to develop a jquery script which will open a popover containing the webpage when you hover over a table td and close it when you move off of it. So far this is working pretty well . The code I have is:

var html = "";
var $that = "";
var $url = "";

$('td').hover(function() {
    var contents = $(this).html();

    if (contents.match("^http")) {
        console.log('contents', contents);
        $that = $(this);
        $url = contents;

        $.ajax({
            type: "POST",
            url: "/echo/html/",
            context: $that,
            data: {u: 'http://ift.tt/gbk8l4'},
            dataType: 'html',
            error: function(jqXHR, textStatus, errorThrown) {
                console.log('error');
                console.log(jqXHR, textStatus, errorThrown);
            }
        }).done(function(html) {
            console.log(' here is the html ' + html);


            html = '<ul class="nav"><li><a href="#">hola</li><li><a href="#">hola2</li></ul>';
            $link = $('<a href="myreference.html" class="p1" data-html="true" data-bind="popover">');
            $link.data('content', html);
            $(this).html($link);

            $that = $(this);

            // Trigger the popover to open
            $link = $(this).find('a');
            $link.popover("show");

        })
    };
}, function() {
    console.log('this2 ', $that);
    $link = $that.find('a');
    console.log('$link2 ', $link);
    $link.popover("hide");
    $that.html($url);
});           

and you can see it at:

JSFiddle

The problem arises over inserting a webpage into the popover via an ajax request. You can see what happens if you remove the line:

html = '<ul class="nav"><li><a href="#">hola</li><li><a href="#">hola2</li></ul>';

It no longer works. What am I doing wrong and is it possible to load a full webpage into a popover given all the unpredictable js within in?