I've had this problem before, but thought I would see if anyone else had this happen. It says that I am in a guild. Shows all of the guild in my list down at the bottom and also puts the guild name in front of my name on chat, but only I can see it. When this happens, I am able to visit each guild member it shows, I am able to trade with them etc.
http://i217.photobucket.com/albums/c...titled-8-1.jpg
