I've had this problem also. I was able to get the pistons to glitch by powering it like so: http://i.imgur.com/kuzsN.png However, it only happened to me while the top piston was pushing sugar cane. If no sugar cane was in the way of the top piston, it would retract normally.
Here's a screenshot of the way (I think) Matthew did it: http://puu.sh/1iJUO You can see the top piston is both retracted and extended. It also only happened to me while it was pushing sugarcane.
It was in snapshot 13w07a, but after trying to input that it said it was invalid and there weren't any matching versions on the menu. I thought it was appropriate as snapshots are a preview of the upcoming version..
Mark scape
MC-10987
I've had this problem also. I was able to get the pistons to glitch by powering it like so: http://i.imgur.com/kuzsN.png However, it only happened to me while the top piston was pushing sugar cane. If no sugar cane was in the way of the top piston, it would retract normally.
Here's a screenshot of the way (I think) Matthew did it: http://puu.sh/1iJUO You can see the top piston is both retracted and extended. It also only happened to me while it was pushing sugarcane.
It was in snapshot 13w07a, but after trying to input that it said it was invalid and there weren't any matching versions on the menu. I thought it was appropriate as snapshots are a preview of the upcoming version..