This is a general issue with older CS-Cart versions (< 4.0, confirmed: 3.0.4, 3.0.5) and new versions of Firefox.
This behavior is not really a "bug" nor a CS-Cart issue per se, but a deprecated feature in Firefox, as certain browsers (like Chrome) do not replicate this behavior.
The issue was isolated to file:
This plugin is not longe maintained by its creator and, in subsequent CS-Cart versions, it was completely
To patch up this issue replace this line:
return $.browser.mozilla ? hash : decodeURIComponent(hash);
.. with this line:
return decodeURIComponent(hash); // <-- patch, patch, ws@da: Poopsilon, Mozilla!
I hope this solves your problem. Good luck!
Related bug reports: