Obviously I agree with those who recommend we just ignore her. He/She will stop after we stop giving reaons for the imposter to hang around. A lot of guilds have been ruined by internal strife as members who argue within. I really don't wanna fuel the fire by giving any additional ammo here but it is sad when people stop realizing it is just a game and just for fun.
The ones who cause trouble over and over will continue until the fun is sucked out of the experience and they are the only ones left. Look for people who try to divide a guild by making them choose sides. Once that has begun, it is difficult to regain control and set things back in order.
It only takes a few bad apples to ruin it for the rest.
Ben Firespinner lvl 40 and Dog Dreadwash lvl 39