Файл administrator/components/com_virtuemart/classes/ps_product.php
Заменить
$q = "SELECT product_id, product_name, product_parent_id, product_thumb_image FROM #__{vm}_product WHERE product_sku='$product_sku'";
на
$q = "SELECT product_id, product_name, product_parent_id, product_thumb_image, product_sku FROM #__{vm}_product WHERE product_sku='$product_sku'";
И добавляем в
$tpl->set( 'product_id', $product_id); $tpl->set( 'product_name', $db->f("product_name") ); $tpl->set( 'show_product_name', $show_product_name );
кусочек
$tpl->set( 'product_sku', $product_sku );