[Koha] Adding new item type icons

How do I add new item type icons to my selection in Koha 3.0.1? In Koha 3.0, all I had to do was add a new folder of icons to the itemtypeimg folder and they would show up under a separate section on the Add Item Type and Modify Item Type pages. In 3.0.1 where there is a separate tab on these pages for each folder of icons, no tab appears for my new folder. What else do I need to do? Thanks. Paul