Bug in JQuery UI when using <base> and tabs()?

Please take a look at the following link:

http://www.ballot-box.net/login5/appearance2.poll.php

When I view this page in Chrome 28.0.1500.95 and Opera 12.16, the page jumps to the main page http://www.ballot-box.net/. In IE 8.0.6001.18702 and Firefox 12.0 the page loads fine.

I noticed that this happens because I’m using both the HTML <base> tag and the jQuery widget tabs() in my webpage. If I remove the HTML <base> tag then the page does not jump to http://www.ballot-box.net/. Is this a jQuery UI bug?