Well, I figured it out, so I thought I'd post it.
Aw man. I got hacked (or something) and an obviously spam message got posted in my twitter feed. Of course, I've had my account suspended, pending investigation. I should be back up within a month, according to twitter. I don't know whether the error is twitter's or mine, but needless to say every place where I used the same password as for twitter has been changed, just in case. All in all, not as painful as it might have been, I guess!