Crafter's name disappeared

My brother had crafted me 2 pieces of Armorer's hand and feet. About a week ago his name was list there at the bottom. Now it doesn't show up and just shows a blank spot where it is suppose to be. Any help? Thanks

Link to a screenshot below
http://i.imgur.com/PaOm96G.jpg

known/common glitch I think. The Market board is full of items that lost the signature.

Those missing signatures will still show up on Lodestone character gear. Only in-game display of certain sigs seems to be borked.