There is an issue with the latest version of Firefox that can cause it display an old version of an online shopping cart or website even when they have been updated. We are currently working on a solution for this.
Update: This issue is fixed in the latest version of Firefox. Please download and install it from mozilla.org/firefox.
Note: This issue applies to an older version of Firefox.
Until that is ready, you can work around the problem like this:
Hold down the Shift key while clicking the Reload button in Firefox.