The css jquery element is a fixed element on the right. BUG animation in Firefox

I created a fiddle for my question:

fiddle

$('#move').click(function (e) {
    e.preventDefault();

    $(this).not('.up').animate({
        bottom: '50%'
    }, 1000, function () {
        $(this).addClass('up');
    });

    $('.up').animate({
        bottom: '0%'
    }, 1000, function () {
        $(this).removeClass('up');
    });
});

There is an error in Firefox (my version: 19.0.2).

When you press the red button, it goes to the right (the distance has exactly the width of the scroll bar). when it is on the right and you resize the window (or fiddle-frame), it bounces back.

Am I doing something wrong? Is there a good solution to fix it?