My product categories seem to be malfunctioning, and it is not isolated to any one. Some of them work fine and others do not when I like to them either via the products page (grid view show categories) or with shortcodes. It seems fine in Chrome, randomly does not work in Firefox, and fails miserably in Safari.
I receive this error when using Firefox and Safari when I go to a Product Category Page:
Fatal error: Call to a member function have_variation_groups() on a non-object in /homepages/5/d199347309/htdocs/coffee/wp-content/plugins/wp-e-commerce/wpsc-includes/product-template.php on line 1397
Website: CQ Coffee Roasters
Using latest plugin, wordpress, and Aggregate theme. Any help is appreciated. Also, if you could reference what files you would change if you know of the fix that would be appreciated.