This is not true for several foreign countries, for which one can maintain a dual citizenship with the US. However, Indonesia is not one of them, so Obama would have lost any American citizenship he may have had when he became an Indonesian citizen. His becoming an Indonesian citizen would have negated any natural born US citizenship he may have enjoyed at birth, thus making him ineligible for president even if he were born in Hawaii, which seems doubtful.
And we have a winner. Barry needs go go back to Indonesia. I hope he likes some rooti with his arugula.