The things one learns on Free Republic.
That number was actually on the low side. Here is the citation to back up the claim.
A normal and routine aspect of adoption law is the creation of a replacement birth certificate normally listing the adopted parents as the parents at birth. These documents are factually untrue, but they are never the less valid legal documents for most intents and purposes.
There is evidence to indicate Obama was adopted in 1965 by Lolo Soetoro, and if this is in fact true, whatever he had in the way of a real Hawaiian birth certificate would have been sealed by court order and a replacement birth certificate would have been issued to him naming Lolo Soetoro as his father.
There is evidence that this court proceeding was overturned or modified in 1971 when both Barack Obama Senior and Stanley Ann Soetoro happened to both be in Hawaii at the same time. (Christmas 1971)
For a multitude of reasons, it is not unreasonable to believe that what Barack Obama is currently touting as his birth certificate is in fact a later day created replacement birth certificate issued by the State of Hawaii, and one not necessarily containing accurate information.