Asfaia login server creates all the ids as lowercase anyway nothing to do with that,
The idx lists all the ids in alpha order, with what it seems creation data as the second order of listing.
If you were to create a duplicate id with an earlier creation date then it would auto be default id details, pass etc. The old id would be inert and just be added fat on the database.
Since the char database is linked only by the ID then it causes a problem. Just like the program that fooled the char database into thinking you were on that ID, if you knew someones ID you could create it and be the new owner of the characters.
And no I havnt recreated it but its a little worrying finding two IDs that are identical