MP Checkout confirmation page problem

I'm having trouble figuring out what the issue is here.

I've created a one-page checkout system of sorts. I'm using the wp_ajax_mp-update-cart action and made adjustments to the update_cart function inside marketpress.php

I'm using if(DOING_AJAX) similar to how its used with the widget implementation and depending on the checkout_errors etc I return the correct mp_show_cart() formatted with JSON to my AJAX function.

I'm using Authorize AIM that I modified to work as a global cart plugin. I've successfully taken orders already with the payment gateway so I know that it works.

Everything works great from shipping to checkout to confirm-checkout but breaks on the final confirmation page. When I get to the confirmation page my $_SESSION variable is null so it obviously throws the oops you skipped a step error. The $_SESSION isn't being unset in its correct location inside the template_functions because I tried commenting it out to see if maybe I was clearing the SESSION first then trying to display the content to the user resulting in an error.

Ok so here is the most frustrating part. I have two identitcal rackspace servers one for development and one for production. They are mirror images with the one exception of a self-signed SSL certificate on the development and a godaddy signed premium SSL certificate on the production.

The whole thing is beautiful on the development server. No flaws at all, $_SESSION makes it all the way through the orders are created successfully and everything. Production server is an epic fail with the $_SESSION null.

Any help is much appreciated.