This is an issue with how FireFox serves cached pages when you use the Back button.

There appears to be two ways of solving this:

1. Per the first answer here, set autocomplete="off" for all form elements that can be disabled. As that form likely isn't one you have direct control over (without hacking a module), you'll have to do this with a hook_form_alter().

2. The second answer in the question linked above provides some JavaScript that you can use to stop this from happening:

   window.addEventListener('pageshow', PageShowHandler, false); window.addEventListener('unload', UnloadHandler, false);

   function PageShowHandler() { window.addEventListener('unload', UnloadHandler, false); }

   function UnloadHandler() { //enable button here window.removeEventListener('unload', UnloadHandler, false); }

This is an issue with how FireFox serves cached pages when you use the Back button.

There appears to be two ways of solving this:

1. Per the first answer here, set autocomplete="off" for all form elements that can be disabled. As that form likely isn't one you have direct control over (without hacking a module), you'll have to do this with a hook_form_alter().

2. The second answer in the question linked above provides some JavaScript that you can use to stop this from happening:

   window.addEventListener('pageshow', PageShowHandler, false); window.addEventListener('unload', UnloadHandler, false);

   function PageShowHandler() { window.addEventListener('unload', UnloadHandler, false); }

   function UnloadHandler() { //enable button here window.removeEventListener('unload', UnloadHandler, false); }