I tried many ways to make this work, but the winner was putting the script " <script type='text/javascript' src='http://my-site.com/wp-content/plugins/woocommerce/assets/js/frontend/add-to-cart-variation.min.js?ver=1.6.5.2'></script> " in the head of template.php in the templatename\layout folder and it worked for me! ... now recovering from banging my head against the wall.
James