Had someone complaining they hadn't gotten their registration confirmation so I started checking in case something got broken here. Lo and behold: the advanced email checker was throwing an error. (Funny but the person who didn't get their registration email didn't mention that - and there was no listing for that error in the error log for his IP address, even though other registration attempts triggered it. Kind of hard to register if you don't hit the submit key.) 

BTW, it's fixed here and the problem is not in the SVN trunk. It was an experiment here that failed.