One of the best firefox addons you will ever find Puntuado con 5 de 5 estrellas

The simplest and most intuitive FTP tool ever.I have been using this tools for a long time now and it is just great!! It has never failed on me!

Esta valoración es de una versión anterior del complemento (2.0.14.1-signed). 

What's the issue you're having? Do you mean Firefox 21 compatible? (instead of 12)