I dont recall modifying those things... but maybe.. I dont have admin/functions.php but I do have admin_functions.php ... here is my admin/categories.php
and admin_functions.php
I would love to get this working correctly.. I guess these files are to big to post inline so I have to attach them.
If I try to place the newest categories at the beginning, everything works except the thumbnail is no longer shown. However, if I Place them at the end the thumbnail works fine.
Eventually I would like to request a mod to randomise the category order, but until then It would be great to get this working.