I'm afraid the Firefox Extension really lets the NordVPN side down. It's great while it works, good performance and security but suddenly, for no apparent reason, it won't let you browse anything on the Internet. It looks like the Internet connection has dropped at first but it hasn't (Outlook continues to work). Turn the extension off and everything works again. It isn't the Internet Kill switch, this happens whether it is off or on. It's a great pity, I feel a darn sight safer with this on and working but it is just too unreliable.