When a map is reloaded, extended pistons seem to "retract" yet not retract as it doesn't move (so it is not really noticeable). However, if an object, such as a sign or a ladder, is attached to it, it will break when it is loaded.

By reloading, I mean exiting and rejoining the game.

This bug is reproducible. Activate a sticky piston, put a block at the end, then put a ladder. After reloading, it will break.

Also, the version is 1.0.4 not 1.0.4.11 , I dont think 1.0.5 or 1.0.4.11 was released.