WP-ecommerce Products Group Page not showing Products and description

I’m using WordPress 2.9.2 and WP-ecommerce plugin 3.7.5. I upgraded WP-ecommerce plugin to the latest version (3.7.6) and it completely screwed up my site so I rolled back to the old version. However, after the roll back, the product groups/category page is showing the same content as the main products page.

Main products page: http://sparkposts.com/sparkposts-products-and-services/
Example of a product groups/category page: http://sparkposts.com/sparkposts-products-and-services/article-writer-and-blogger-packages/

Before the upgrade, when things were still working as they should, the product groups/category page should show the description of the product group, and a list of the products in that group. Now it shows the same content as the main products page.

Please someone help…. I’m desperate.