No, at the time of his birth Obama was not a U.S. citizen and because his father is not a U.S. citizen he never could have been a natural born citizen even if his birth had been in the U.S.
This time you are correct.
Re: “at the time of his birth Obama was not a U.S. citizen “
If born in Hawaii, Obama was, “at birth,” a 14th Amendment “statutory” US citizen.
http://www.theobamafile.com/_eligibility/IssueFourCases.htm#Obama