fields dissapearing

-- HikaShop version -- : 2.6.1
-- Joomla version -- : 2.4.8
-- PHP version -- : 5.4

Good afternoon,

A slight snag on the category configuration in the back-end:

After setting the fields "layout on product page" in "additional info" from "inherit" to hikashop default the entire option disappears in the back end. No going back here.

It seems that altering this setting leads to no output in the front end and as for now I have no option to change back to the original "inherit"setting as the entire option/button/bar is not displayed in the backend anymore.

I've added a printscreen with a category with this problem and one category without this problem.

Kind regards,

Chantal