derp pistons are back again in snapshot 14w26c
to reproduce:
1. build what is shown in 2014-07-01_13.56.55.png away from the world spawn, if you dont build it away from the world spawn it wont work

2. pull the lever and the pistons will start going up and down

3. save and reopen the world and one of the pistons will turn into a derp piston