ToME: the Tales of Maj'Eyal

When I try to log into the online profile within the game, I am unable to do so. OK, I ask for a new password. Go through and get one-time login, no problem. Try to change password, and I get an error saying the email address has already been registered. Um, yeah, it would be hard to change the password if it wasn't!

I suspect the problem may be that I've somehow created two accounts connected to my Facebook account, but I'm really not sure. Any ideas what I can do about this?