Re: Adding gift certificates calculates wrong shipping
Since this was an upgrade - try this first. Uninstall all of your payment, shipping and order totals modules. ( be sure you have the settings used written down)
Close your browser.
Count to 10
Reopen your browser, go to the Admin and install your payment, shipping and order totals modules. Do not install any modules that you are not going to use.
Please do not PM for support issues: a private solution doesn't benefit the community.
Be careful with unsolicited advice via email or PM - Make sure the person you are talking to is a reliable source.