Have you already posted about this issue? If so, DO NOT POST a duplicate. Instead, reply to your existing post, with MORE information.
What version of Zen Cart are you using?
Has your site been upgraded? When? From what version(s)?
If you've upgraded, HOW did you upgrade? (official upgrade procedure or an automated script from your hosting company?)
What addons have you installed? When? I have the USPS shipping addon, the Amazon Checkout addon, the editable sideboxes, the testimonials... I think that's it. They were added several days ago at the most recent, and the gift certificates were working find after all of that.
HOW did you install it? (upload via FTP and run zc_install, or a one-click install from your hosting company? (one-click installs are NOT recommended))
In what ways is your site customized or different from a brand new uncustomized install?
If you're encountering display/layout problems, post your site URL* so it can be seen in action.
If you're encountering problems that could be related to your server or hosting company, include the name of your hosting company (not their URL). -- Hostmonster.com but I doubt it's related to them as it was working fine the day before.
HAVE YOU LOOKED IN THE FAQ AREA for answers to your question? (ie: a search for your error message or what you want to edit/change, etc) Yes.
Have you searched the FORUM for your error message or for answers to the question you're asking? Yes.
WHEN did the problem "start"? How does that compare with other events of your hosting company, changes you've made to your site files/addons, or your admin settings, etc? The problem started yesterday. I did change this domain to be the primary domain on my account, but all that affected was my email forwarders. I did edit the shopping cart template and made some CSS changes, but I don't remember editing anything related to the gift certificate pages... though if I knew which one was the problem I could go look...
If this is your first store, have you tested all aspects of transactions before going live? This is my first store and it isn't truly "live" yet, though I have had some friends look at it, and one friend who has tried my product posted a testimonial. I have been in the process of testing all of the transaction possibilities--that's what I was doing when I discovered this problem.
The url is http://opalessenceshop.com if you want to look at it.
Yes, I've cleared cache and cookies--didn't help.