> One is the MtGox problem where you might not realize a transaction was successful and you are duped into sending the money twice. This isn't really a mallea

> One is the MtGox problem where you might not realize a transaction was successful and you are duped into sending the money twice. This isn't really a malleability issue however. Lets say it wasn't successful: You send again. Opps, someone pulls the original out of a hat and both go through. The only way to safely reissue is to double spend the original transaction. Then you get atomic exclusion, and it's completely safe: only one can possibly get into the longest chain. This safety still applies if there is mutation going on.