When i tryed to build a key card reader then it did not work,first i thought that it was something wrong with my redstone but then i realized a bug with the dropper and saw that when i tryed to drop something into the hopper than the item got stuck and i knew it was a bug because in mc java ,console and earlier versions mcpe have not the problem.I think it started in 1.1 and is still affecting 1.1.0.3.Most of my redstone use this construction including t flip flops in mcpe.So the bug breaks most of my redstone