[_ck_]

If you are asking what I think you are asking, I think I have made the subtle change you need. The sub-forums will no longer be shown on the front-page.

http://pastebin.com/m5ce19f4b

Line 53 is really all that’s needed.

if (!$forum->forum_parent) {

This is untested however.

Topics from within the sub-forums will still showup in the latest discussions however.