Picked up on this a bit late, because I've been working on graphics stuff. Looks like a repetition of the Dan Rather National Guard story, where bloggers with expert knowledge spot a forgery.
What puzzles me: The date or place of birth wouldn't have been a reason to discard or forge a certificate. I seriously doubt that Barack's mother had a prophetic vision of her baby's destiny as President, and even if she did, the whole "natural-born" thing is fairly arcane. Most people wouldn't list it among the top ten criteria for a President.
Given that the mother and grandparents were hard-line Soviet supporters, which I've discussed
before, it seems more likely that the hapless Kenyan student Barack Sr was simply a convenient placeholder. I'd guess that the real father was a prominent black Communist of less exotic origin, who had a reputation to maintain. In those days, even among Bolsheviks, illegitimacy was a serious stain.
Just for a random example, Barack Jr looks a lot like Julian Bond.