When you have a problem with one particular site, a good "first thing to try" is clearing your Firefox cache and deleting your saved cookies for the site.

(1) Bypass Firefox's Cache

Use Command+Shift+r to reload the page fresh from the server.

Alternately, you also can clear Firefox's cache completely using:

Firefox menu > Preferences > Advanced

On the Network mini-tab > Cached Web Content : "Clear Now"

If you have a large hard drive, this might take a few minutes.

(2) Remove the site's cookies (save any pending work first). While viewing a page on the site:

• right-click and choose View Page Info > Security > "View Cookies"
• Tools menu > Page Info > Security > "View Cookies"

In the dialog that opens, you can remove your Amazon cookies without affecting other sites.

Then try reloading the page. Does that help?

Removing the site's cookies worked! Thanks!

That did not work for me.

Oh, and the "customer support" guy's first suggestion was to use Internet Explorer instead. I said "Hell no! I'd rather jab myself in the eye with a rusty fork than use Internet Explorer." Then he told me to try another browser. I said I don't have another browser. Then he told me to clear my cookies and log in with https instead of http. Of course, doing what he suggested did nothing but waste my time because I still got an error page instead of a successful checkout. Then I got the usual baloney about how he'll tell tech support about this problem and it will be fixed in a few hours.

The problem is clearly on their end; I have no problem shopping on other websites. So, if you'll excuse me, I need to go shop somewhere other than Amazon until they fix this problem.