User Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:30.0) Gecko/20100101 Firefox/30.0 (Beta/Release) Build ID: 20140605174243 Steps to reproduce: http://www.change.org/en-AU/petitions/australian-government-to-pressure-egypt-to-free-peter-greste-and-his-aljazeera-journalist-colleagues Sign the petition Actual results: failed to sign Expected results: It should sign. I've checked it in Chrome and there is no issue. Will review with plugins disabled.
Works with addons disabled. Yet there was no need to disable addons in Chrome.
This is likely because of a filter setting in your adblocker and not a bug in Firefox. Try to find the filter rule and disable it or disable the adblocker on this specific site. Maybe you should contact the add-on developers: https://adblockplus.org/en/bugs