Nice mod, just what I´m looking for.
But it did require some extra work to get it working on v4.1.3
I doublechecked all your instructions but I kept getting SQL errors on my pages.
I found out that the SQL-error disappears when I remove 'as' from the line
Code:
$fields[] = "$sql_tbl[images_P].image_path as ";
in func.product.php.
Now the thumbs do work when viewing a product, but when viewing the products in a categorie (products.tpl) they still aren´t passed using the thumb function. instead they are generated by image.php, which means that for product_thumbnail.tpl both the $tmbn_path_p and $tmbn_path_t variables are empty. Why isn´t func.product.php filling those?