Select woo doesn’t appear to fire ajax and get the price

we’ve got a WooCommerce site that has sometimes up to 3 variation select boxes on a product, as the variations are selected it should refine the options in the other boxes and generate the correct price.

Our standard select boxes work, but when we apply selectwoo() to them it appears to select the correct item, but it doesn’t refine the other select boxes or display the price. We’re guessing the ajax for doing this isn’t firing, but can’t figure out why (we’ve been searching for ages).

This is our code:

<link rel="stylesheet" href="<?php bloginfo('template_url');?>/css/selectWoo.min.css" />
<script src="<?php bloginfo('template_url');?>/assets/js/selectWoo.min.js"></script>
<script>
$(document).ready(function() {
$('.product-wrapper select').selectWoo();   
});
</script>

What are we missing?

Thanks ??