When i put an enchanted item in my hand my FPS just go down and i start to lag a lot. This bug affect more people (Search on google: Enchanted Glow Lag or Lag Enchanted items). Also if i see someone in multi player using diamond armor the FPS go down a lot too. This thing appeared to me in Minecraft 1.6 , but in some other people started in Minecraft 1.5 .