If you generally use Firefox, and you wish to check the status of 301 Redirects or whether they have been successfully removed, make sure you clear your browser cache.
You can do this by going to Options, then Advanced, in Firefox options (Firefox 16.0.2).
Alternatively check using another browser such as Chrome or Internet Explorer, before worrying that the 301 redirect hasn’t been removed, as Firefox will cache 301s unless the website header takes steps to remove the cached version.