Dean Radish on "[Plugin: WP-Filebase Download Manager] Latest version (3.1.02) not showing categories and files"

Hello,
I think you are right to suspect an ownership issue.
In version 3.1.02 I had an issue with categories that I had created using an earlier version. My categories were created and therefore owned by user with id '1'. I had subsequently changed the id of that user with no problems. After an upgrade to 3.1.02 the categories were not displayed on the 'Manage Categories' screen although they still appeared in the uploads folder and on the database table wbfb_cats. I corrected the value in the cat_owner column and my categories reappeared.
I changed the value using 'MySql Workbench' or you could use phpMyAdmin or a similar tool provided by the web site host. I'm not aware of any way to change the ownership of categories using the front end unless you are prepared to create a new one and delete the old one.
regards
Dean