Ok all thanks to Pixclinic. Forget prior package, the demo site doesn't even use, and Jquery is needed?

Go with this
in product_info.php: the button that adds to the wishlist is coded as follows:

CODE
echo '' . tep_image_button('button_wishlist.gif', 'Add to Wishlist') . '';


in application top, before the shopping cart actions:

CODE
//Wishlist actions (must be before shopping cart actions)
if(isset($HTTP_GET_VARS['wishlist_x'])) {
if(isset($HTTP_GET_VARS['products_id'])) {
if(isset($HTTP_GET_VARS['id'])) {
$attributes_id = $HTTP_GET_VARS['id'];
tep_session_register('attributes_id');
}
$wishlist_id = $HTTP_GET_VARS['products_id'];
tep_session_register('wishlist_id');
}
tep_redirect(tep_href_link(FILENAME_WISHLIST));
}

More...