Video example.
I can confirm this as well. It's not just this setup though. I was using a double hopper timer with two sticky pistons pushing a block of redstone back and forth. Twice when I came to check on the timer, the block of redstone was gone, and one of the sticky pistons was gone as well.
Continues prevalently in 1.7.1
Confirmed in single player; no framed maps.
Noticed this with large amounts of animals in a small area; they are being pushed through fences by the other animals. This problem is possibly related to zombies being able to attack villagers/players through fences/doors.
This code works perfectly! It needs to be implemented.
http://www.minecraftforum.net/topic/1920678-162-unglitch-fix-for-escaping-animals-and-more/
Affects 1.21.22.01
Affects 1.19.21