They have a thread for this in the Known Issues forum on the Outspark forums. They basically think that the problem lay in the guild's message had to be under 25 characters or something like that? I dunno. But I guess it's getting fixed in the next patch. -.-

Oh. Well, to be honest...I don't really care. I think I've played enough fiesta for a week. I find FiestaFan to be a lot of fun :x I'd rather be on here and talking to people on aim and stuff, than be in game.