Now that shouldn't be possible in a chain without forking back to the block that contains the transaction ... unless the encryption keys used are part of a key pair that someone else has the 2nd part of for all access.
That would make releasing the source code rather a MAJOR problem
![Smiley](https://bitcointalk.org/Smileys/default/smiley.gif)
(or if someone bothered to decompile it they could find how to get this key ...)
So either none have been reversed, or everyone using SC2.0 is in even more serious trouble than already stated.
Also, the fact that every 2nd block is low difficulty also says that the chain itself is not secure to the network hash level - technically, only half that
![Tongue](https://bitcointalk.org/Smileys/default/tongue.gif)
(and what does everyone hash while waiting for the 2nd block to appear?)