I just noticed that the Captcha on the registration form was faulty (I’m not sure how long for) which made it impossible for anyone wishing to join in discussions here to register. I’ve fixed it now. My apologies to anyone affected.
Please be assured that the site welcomes new members and I invite those who have tried and been unable to register to have another go. If you experience any difficulties, please email me at firstname.lastname@example.org. (Unless you are a spammer, of course!)