I up-to-date my checkout page by upgrading mostly the file that was ins...wordpress-ecommerce/wpsc-theme/wpsc-shopping_trolley_page.php

It labored fine for some time, however a few of the transformed states reverted towards the previous condition. Really, I'm able to even remove the file which i pointed out above, therefore it means wordpress is loading this file from elsewhere. Any ideas where and what had happened? Interesting help.

Although I do not possess a specific response to your question, if you are using an IDE (like Dreamweaver or Eclipse) you can grab a duplicate of the sites code for your local PC and perform a code look for something that's unique to that particular page.

Ie, if there's a <div class="a_unique_div"> tag somewhere on that page and also you know it's only visible on that page, search the code for your also it could give you an idea what file has been employed for the output. Even when it's only utilized on one or two pages it might provide you with nearer to working it.

Alternatively, for those who have SSH access you could attempt and "grep" for that code by SSHing to your server and managing a command like:

grep -i -R '<div class="a_unique_div">' /www/your_wp_folder/

(where /www/your_wordpress_folder/ is the road to your WordPress installation)

Though with this you will need SSH access, grep placed on the server, etc, so it might not be a possible option.

Best of luck!