Spam bots tend to behave differently from genuine commenters using standard browsers. Thus my web site rejects any comments coming from a browser that behaves in an unusual fashion. If, for privacy or security reasons, you have your browser set to behave in an unusual fashion, your attempt to comment may well fail. If you cannot comment, try using another browser to let me know about the problem. Similarly if you encounter those accursed captcha tests. Use another browser, or sacrifice some privacy.