I'm trying to use the SEO sitemap contribution as well. I can't get very far. After I upload the files: sitemap_categories.php sitemap_products.php sitemap.js index.html includes/sitemap_includes.php includes/application_top_sitemap.php includes/application_bottom_sitemap.php I get this error when trying to visit sitemap_categories.php to check the upload: Fatal error: Class messagestack: Cannot inherit from undefined class tableblock in /usr/local/www/data-dist/secretsunveilled.com/catalog/includes/classes/message_stack.php on line 20 The installation of OSCommerce works fine. no errors. haven't changed any settings, just uploaded the files listed above as the instructions stated and tried to visit the one page. Anyone have any idea how to fix this? Thanks.