Can you please export the structure of the attachment table (wcf1_attachment from freebeat database), structure only, with phpmyadmin, and attach it or send it in a PM?
In order to do that, you can select the database and the table, then go to export tab, and please make sure you select "structure" only, no data. Then save it in a file, and PM me the contents of it, or attach it here. Having no data whatsoever, it wouldn't have anything confidential.
Alternatively, if you wish, I would appreciate if you consider to send me the entire contents of the database, that would help. As you want, of course.