Secure Password Generator от Nikolay Martynov

This add-on allows you to easily create random and secure passwords.
Right click on any password field on the webpage and select "Secure Password Generator"/"Generate password". Newly generated password will be inserted into selected field.
You can use "Insert previous password" context menu option if form requires you to repeat your password.
You can also use "Secure Password Generator" button in top right corner of Firefox window to see last generated password, change settings and create new secure passwords.

Hope this is useful. :)

If you find problems with new version please leave bugreport here. Thanks!