It would be best to disable the shipping quotes directly on the confirm page. This will require some hand editing of the page though. If you can post back with the confirm page in a zip archive I will take a look and edit the page to disable the shipping quotes. This way you can see if there are any other problems with the checkout.
Based on the result you are getting compared to what I was getting it seems that you are not actually triggering the quotes since the full request and response are not present.
To add the page to a zip archive you should be able to right click on it and send to zip or archive depending on your os.