Paulus said:
What if this was the method being used by the hackers.
One open up a terminal server session on the PC.
Then open up another instance of final fantasy and log in.
This would depend on if the user could open up a text file with your password. (Sucks to be you if your password never changes)
After the second instance of ffxi is open they log in.
To you on your own session this may seem nothing more than lag as you can't actually see the resources being used on your PC.
I'd do a netstat check to see if there's anything unusual. Even if it's a new session netstat would still see all connection pumping in/out of the NIC.