Thanks to a combination of heavy traffic and a side effect of moving some databases, we had a problem with notifications not being delivered (both via email and the on-site inbox). mark has identified the issue and fixed the underlying problem. The delayed notifications should be sent out now as the workers catch up with the backlog.

We're sorry about the problem!

EDIT, 7AM EDT: after fixing the problem with notifications in general being severely delayed, we're now seeing that AOL has placed us on their "you send us too much mail" blacklist and is refusing all mail from us. We'll see what we can do to get the block listed, but we can't guarantee anything. If you use an @aol.com or @aim.com email address, you may want to temporarily switch your email address to a different email address under your control in order to be sure you don't miss mail.