As far as I know, that is not true. If you have evidence to the contrary, please provide it.
It is true. Look it up yourself.
http://leahy.senate.gov/press/200804/041008c.html
IN THE SENATE OF THE UNITED STATES
Mrs. MCCASKILL (for herself and Mr. LEAHY, Mr. OBAMA, Mr. COBURN, Mrs. CLINTON, and Mr. WEBB) submitted the following resolution; which was referred to the Committee on
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RESOLUTION
Recognizing that John Sidney McCain, III, is a natural born citizen.
Whereas the Constitution of the United States requires that, to be eligible for the Office of the President, a person must be a ‘‘natural born Citizen’’ of the United States;
Whereas the term ‘‘natural born Citizen’’, as that term appears in Article II, Section 1, is not defined in the Constitution of the United States;
Whereas there is no evidence of the intention of the Framers or any Congress to limit the constitutional rights of children born to American citizens serving in the military nor to prevent those children from serving as their country’s President;
Whereas such limitations would be inconsistent with the purpose and intent of the ‘‘natural born Citizen’’ clause of the Constitution of the United States, as evidenced by the First Congress’s own statute defining the term ‘‘natural born Citizen’’;
Whereas the well-being of all citizens of the United States is preserved and enhanced by the men and women who are assigned to serve our country outside of our national borders;
Whereas previous presidential candidates were born outside of the United States of America and were understood to be eligible to be President; and
Whereas John Sidney McCain, III, was born to American citizens on an American military base in the Panama Canal Zone in 1936: Now, therefore, be it
Resolved, That John Sidney McCain, III, is a ‘‘natural born Citizen’’ under Article II, Section 1, of the Constitution of the United States.
http://leahy.senate.gov/press/200804/041008c.html