Your SE ID is what you created for the site.
OLD System:
Member ID (User Generated)
POL ID (System Generated)
You created a new SE ID for use with the SE Account management system and these forums. This is the account that you have to link your POL ID with to be able to play FFXI now.
Sign into the SE AM System and go to "List Options Continued Automatically". At the top, you will see a drop box for selecting your linked ID's, displayed as:
Playonline/Final Fantasy XI: ABCD1234 [Region]
If you scroll down towards the bottom, you will see buttons for updating information. Click the button to update your password and make sure it is the same one that is saved under your Playonline settings for the game in the top section of the login settings (not the middle part, that is a local password for launching POL, the top part is for authenticating to the server). If these two saved passwords (one in SE system, and your POL settings) are not in synch, it will trip the 53xx errors.
