The only way he can have “Natural Born Citizen” status is if someone other than Barrack H. Obama Sr. was on the certificate. If no father is listed it does not solve the problem.
If his father is Frank then he would definately be a Natural Born Citizen of the US, but also a Natural Born Commie.
If it came to light that FMD was his real father (thus making him a natural born citizen but also proving that the "autobiographical" books were fraud), I am not sure he'd consider that so damaging that he'd refuse to reveal the contents of his long-form birth certificate. I think it's something else.