Creating new category/folder in Orca?

I don't seem to figure out how to do it?
Any idea?

Admin -> Modules -> Orca Forum -> Then click on the link Manage Forum

Add new groupe -> click on the link New Group (to right for the title Manage Forum)
Add new forum   -> click on the folder icon to right side for the group were you will add a new forum bellow

How to manage forum:
1) Add new groups
2) Add new forums bellow your groups

if you have done 1 and 2, you can now go to your new forum and add a new topic...
new topic can only be added to a forum, not to a group...hope you understand what I mean...