Page jumps slightly on AJAX Submit

If you click the "Stay Up-To-Date" tab in the upper right on this page:
http://clients.freelancewebdesigner.com/tests/gravityforms/slide-out-forms/
a div containing the Gravity Form will slide down:

The embed code in my template is set to $ajax=true to avoid a full page refresh which would hide the form behind the tab again.

Clicking the Subscribe button with $ajax=true though makes the page scroll (or jump) down just slightly which feels odd and doesn't seem like something that should be happening.

Is there some way to prevent the page jump when clicking Subscribe?

Researching more I've found another thread suggesting AJAX submitted forms still require a page refresh which anchors down the page to the forms confirmation message by default, which I was not expecting.

Issue resolved by adding this to my functions.php:
add_filter("gform_confirmation_anchor_2", create_function("","return false;"));