Mt. Gox CEO Mark Karpeles has been ordered by a judge to return to the US to face questions over his bankruptcy filing with a Dallas court and how 750,000 Bitcoins went AWOL. Bankruptcy judge Stacey Jernigan ruled that Karpeles must appear at the Dallas office of his lawyers Baker & McKenzie on 17th April. This is ahead of a May 20 hearing which will decide whether the Bitcoin exchange will be granted Chapter 15 protection from creditors.