I heard part of an interview with a former FBI agent yesterday who claimed that had Obama applied for a job with the FBI instead of running for president, he wouldn't have made it past the screening process. His application would have been rejected in the first round.
Amazing.
If Obama was a government employee or serviceman in DOD, he would never be given a security clearance. So, that is what I would assume the interview you heard referred to. I would guess most employees in the FBI must have at least a secret clearance. So, if they are interviewing Obama and I'm sure they ask where his parents are from, Obama would get the prompt "Ok' that about wraps up my questions, we'll call you soon".
I've known several individuals in the Army who have a parent that is a naturalized citizen, it is almost impossible for them to obtain a clearance. Or if they have a parent that is not a citizen equals no clearance.