I think I found a bug in the Veronika theme: when the "Category Selection on Publish" parameter is set to "Flat selection (icons)" in the Publish listing page it shows also the categories that have been disabled by the admin.
If I set this parameter to "Cascading drop-downs" or "One select box", the disabled categories are not shown.
Can you help me to fix this? Thank you!

@MrWolf
Thanks for reporting this bug.

Go to file:
oc-content/themes/veronika/functions.php

Find:
findSubcategories
Replace with:
findSubcategoriesEnabled

There are 3 occurences of this function.

Thank you for the quick reply, but this is not a complete fix.
I can still see disabled root categories (while subcategories are now gone with the fix).

@MrWolf
Same as before, but now replace findRootCategories with findRootCategoriesEnabled

Fixed, thank you!