Several customers have reported that when they updated their website to WooCommerce 2.1 some of the functions on their website stopped working.
- variable products there was no Add to the Cart Button
- once l have calculated shipping on my cart page, selecting a shipping service, if l change the shipping service the order total does not update to reflect the correct amount
You will need to uninstall/ delete WooCommerce 2.1 and install the version again.
Download the latest version and install again.