I am having the same issue. I actually think that this is a conflict with a recent wordpress update.
I am testing the interactions of the form and it the console trace shows the following error.
$ is not a function @ https://www.mysite.com/:225
when inspecting this error it brings me to this line within the successful response.
$(‘#mce-success-response’).hide();
I think this is due to errors withing jquery 1.6.1 which was recently upgraded in the WordPress auto update from jquery 1.5.
Going back to jquery 1.5 by placing the following in your themes functions.php file should work.
function my_init_method() {
if (!is_admin()) {
wp_deregister_script( ‘jquery’ );
wp_register_script( ‘jquery’, ‘https://ajax.googleapis.com/ajax/libs/jquery/1.5.2/jquery.min.js’);
wp_enqueue_script( ‘jquery’ );
}
}
add_action(‘init’, ‘my_init_method’);