Firefox 17.0 ? That's an old version, Firefox 24 is the latest version. <br /> http://www.mozilla.com/en-US/firefox/all.html Looks like there's some security issues with that add-on. <br /> http://blog.kotowicz.net/2013/07/jealous-of-prism-use-amazon-1-button.html Plus the user reviews of that extension - https://addons.mozilla.org/en-US/firefox/addon/add-to-amazon-wish-list-button/reviews/ - indicate that extension might not be working correctly as of late.