Looks like our spam filter is too efficient — in other words, it also blocks bona fide comments. Since we get about a thousand spam comments a day, we cannot spend time on sorting out which are sham and which are authentic. [Added 27 Dec.: now we’ve manually moderated all bona fide comments: excuses to Isabelle Dussauge, Mette Kia Krabbe Meyer and David Wootton for being late with this]. When Benny (the new WordPress wizard) returns after New Year, we will ask him to install another filter.
PS: there are so many kinds of filters. E.g., my old friend Alex Pang has one which tells you that “The language of your comment does not match the preferred language of this user”, and then you are invited to do one of those recognize-six-distorted-letters-tests which I always find so humiliating (pattern recognition is not in my primary intelligence repertoire). I mean, what on earth is Alex’s “preferred language”?