I never thought I would be a little paranoid- always a first time. I scramble for old reliable friend Wikipedia. Nothing to the point, then an entry caught my eye elsewhere. Alleging Wiki was absolutely silent on the naming of young Soetoro. Ok, so the jury is still out on Wiki.
It seems early on it was, of course, Barrack Obama Jr. Then Obama Sr left in a hurry. Along came Soetoro, when the lad Obama jr, was about six years old. Off they go to Indonesia. The lad became Barry Soetoro. He is said to be registered as a muslim student there.
Now off goes Soetoro Sr,and Ann Dunham Obama Soetoro is said to divorce him. I presume he(Presidential nominee). was known as Soetoro, his stepfathers name for over ten years. I do stand to be corrected here.
At about 18 years of age, young Soetoro, then changes his name to Barrack Obama.