Okay. But so what? Even if he is a dual citizen of the US and Indonesia, that is not a Constitutional bar to the Presidency.
Yes it is. The office of President requires that you have loyalty to ONLY the United States. The founding fathers took that into account when requiring Natural Born Status. Which also includes not having citizenship in another Nation.
He is ineligble to run. Its up to Obama to PROVE he is.
http://www.usconstitution.net/xconst_A2Sec1.htm Article 2 Section 1
“No person except a natural born Citizen, or a Citizen of the United States, at the time of the Adoption of this Constitution, shall be eligible to the Office of President; neither shall any Person be eligible to that Office who shall not have attained to the Age of thirty-five Years, and been fourteen Years a Resident within the United States.”