So, I was playing in my testing world for 13w04a. I started experimenting with armour. When I right click on armor, it puts it on the next layer up. It happens with all types (chain, diamond, gold, leather, iron.) When you right click a pair of boots, it goes on at your legging section, right click on leggings, goes on your chestplate section, chestplates go on your helmet section, but when you right click on a helmet it chrashes your game. It was a really weird bug/glitch. I will attach the file of the crash report as an attachment.