I think I've figured out what the problem was. Last year, I had the same shipping failure message. I went back and forth here trying to figure out the problem and I'm not sure if it was you or someone else, but I let the web assist helper go into my FTP and change the files so they worked.
Now that I needed to change the price, my dreamweaver uploaded the old code with the new price... hence the same old problem. I'm not sure where to find the files that worked are since I think they were overwritten with the update. The file might have been sent to me via email, but I have since changed my email from firstname.lastname@example.org to email@example.com. Don't know if this helps but I thought I would mention it just in case you guys keep all your old emails, maybe you can find the file that was sent to me with the good code to fix that shipping failure