I just posted a reply to the raincoat question, and I didn't get prompted to prove I'm a human. And I didn't change anything, so I don't know what happened.
Maybe it's triggered by the frequency of someone's postings? If so, it's an undocumented feature, and there's nothing I can adjust in the settings. Or, maybe it was just Bravenet's idea of a Halloween prank on you.
And Bravenet.com is down again (for example, you can't get the smilies), so I would guess that, again, it's relayted to Bravenet.com being unavailable.