Obama should have know that an actual long-form birth certificate wasn't going to quell the mobs. Meet your new conspiracy theorists.
Before you ask, yes, this guy's serious, and there's a lot more where this comment came from. You sort of had to expect this type of thing, which again raises the question of whether Obama should have even put forth his birth certificate.
Conspiracy theorists are conspiracy theorists, and, like a dog chasing its tail, they can entertain themselves for hours with ever new ways to approach a problem. On top of that, some of the birthers are racists, and because being a racist is no longer socially acceptable, they'll forever question Obama's status as an American as a way of marginalizing him without directly attacking his blackness.
Starting today (and about three years too late) you can be pretty sure that the people focusing on the president's birthplace instead of his policies are either new-world-order fearmongers or straight-up bigots. Either way, ignore them.