itwbennett writes: The software driving Bitcoin's network was upgraded Wednesday, with security fixes addressing a problem that defunct bitcoin exchange Mt. Gox blamed for losing nearly half a billion dollars worth of bitcoins. The latest version of bitcoin's software, 0.9.0, contains more than a half dozen fixes for transaction malleability, according to the release notes for the software. Bitcoin Core also contains a new feature for payment requests. Previously, merchants couldn't attach a note describing an invoice, and people also could not supply a refund address to a merchant. The latest version automatically supplies a refund address.