Upgrading to WP 2.8.4 broke my AJAX in Contact Form 7

I’ve been using Contact Form 7 for my inquiry form when I was still using WP 2.7. Everything was still fine and working. Before, when submitting an inquiry, AJAX sends the request and updates the form. Until I’ve upgraded to WP 2.8.4 I noticed the AJAX doesn’t work anymore, the form still sends though. I would like to have that feature back in my form.

I’ve tried to disable all plugins, and comment-out scripts in my function.php but nothing helps. I’ve been using the Photo & Graphic Studio 1.0 theme.

Can anybody point me where to fix and enable my AJAX again? Thanks.