Hi
Sorry I moved the site here are the updated links, as I can't seem to fid the edit post button
3.10 http://widgets.cartonline.co.uk/external-add-to-cart-link-310
3.20 http://widgets.cartonline.co.uk/external-add-to-cart-link-320
I have not had time to test it with 3.3 and 3.4.