A problem identified by Mt. Gox as a bug in Bitcoin software is actually a longstanding technical issue Mt. Gox should have prepared for, the Bitcoin Foundation said Monday. Mt. Gox blamed problems with its currency exchange on a bug in Bitcoin's software allowing for so-called "transaction malleability," giving people the ability to change Bitcoin transaction details after the fact. Fraud could be the outcome and Bitcoin's value has been on a downward spiral since Mt. Gox called out the problem Monday after suspending transactions last Friday.