A new t-flip flop was created to work with the redstone block after Snapshot 13w03a (refer to attached images), however, as of 13w09c, it does not work. Normally, the redstone above the input would power the bottom piston via the block on top, which in turn powers the piston holding the redstone block, but once the piston retracts, the block does not. However, if it is turned on again, the piston extends and pulls the block back. With 13w09c, the piston behind the input it powered, but the piston controlling the redstone block is not.