I noticed when I was working with enchanted items on singleplayer that, when I pressed Esc, everything froze exept one detail: the Enchantment Glint. The glowing animation on enchanted items(or nether star). This happens everytime, wether on 1.5 or 1.6 and I think it has been since the implementation of the enchantments, but I'm not shure.

This is just a little note, I don't even know if it has been noted yet, but I hope it can help.