When I try to challenge one of the Bot Group bots (Kugutsu, GnuGo, etc.), using the latest Firefox, I get the following message: "CSRF Failed: CSRF token missing or incorrect." This is true whether I click on the bot's name in the search or in the Bot Group. What does that message mean? However, I can challenge them when using Explorer, so is this a browser issue? I prefer Firefox, which has greater functionality on the site. Is there any remedy?