Since Thursday, our comment spam filter has been producing a lot of false positives, so that non-spam comments are being blocked. I’ve been trying to check the spam folder every several hours and revive the comments, but that’s a slow and not entirely reliable process. We’re also checking into what the underlying problem might be, and how it might be avoided; I hope that will be taken care of soon, but I’m not sure when.
Unfortunately, the one thing we can’t do is turn off the spam filter — we get about 1000 spam comments each day (real spam, not false positives). So I just wanted to keep you folks posted, and apologize for the problem.