"Invisible", empty piece of gear that I can't get rid of!

Hello! I was on a quest in Coerthas yesterday and a Treasure Chest appeared on the ground (very much like those appearing in Battlecraft Leves, only I was not in one). When I opened the chest, it displayed a loot roll window since I was in a group with my sister. However, there was only an empty gray square in the window with no item name and no description. I "won" the item, and it was placed in my Armory Chest, seemingly in the Body tab. I cannot click on it nor move it, nor place other items into the space it occupies, so it is essentially taking up a space in my chest that I can no longer use!

Here is a link to a screenshot of the phenomenon:

http://imgur.com/a/ZnzWG

The "only gear can be placed in the Armory chest" message appears when I try to put a piece of gear onto the "blank" spot.

EDIT: The item seems to be gone now, after several relogs. Thanks anyway :p