webapps do not take firefox extension questions, for the obvious reason that it's not about applications related to the web. It's about Web Applications.. i.e. server side.

Firefox is a desktop/client app rather than a server app.

They don't like them on webapps
http://meta.webapps.stackexchange.com/questions/804/reason-for-my-question-better-suitable-to-superuser-than-here

http://webapps.stackexchange.com/questions/27299/colorzilla-extension-doesnt-work-in-firefox-12-any-good-alternatives

And they're getting closed on superuser too

http://superuser.com/questions/386757/any-alternative-to-universal-uploader-fireuploader-for-firefox