<s> I'm sorry, how does this relate to Firefox? </s>

Some extension developers really stay on top of Firefox changes and proactively address them, while others ignore Firefox changes until they hear from enough users. I suspect Amazon is in that latter camp, and you may want to pressure them to update it here: [mailto:sendtokindle-feedback@amazon.com sendtokindle-feedback@amazon.com]. Two reviews on the Add-ons site suggested this one as an alternative -- it uses the FiveFilters Push to Kindle service (I haven't tried it myself): * [https://addons.mozilla.org/firefox/addon/kindle-it/ Push to Kindle] * Site: http://fivefilters.org/kindle-it/ * Privacy Policy: http://fivefilters.org/privacy.php ''Send to Kindle reviews page: [https://addons.mozilla.org/firefox/addon/sendtokindle/reviews/ https://addons.mozilla.org/firefox/addon/sendtokindle/reviews/]''