I found it ...
Code:
<!--bof Form start-->
<?php echo zen_draw_form('cart_quantity', zen_href_link(zen_get_info_page($_GET['products_id']), zen_get_all_get_params(array('action')) . 'action=add_product', $request_type), 'post', 'enctype="multipart/form-data"') . "\n"; ?>
<!--eof Form start-->
That fixes it on the template for the product _info ...

You will need to fix the other product types too if you use them ...