I will reply this for my self, I just look arround for a while and find this: It works OK
I just copy and paste here
hi i post this 'cos it's a way to refresh an old post i found on this forum http://wordpress.org/support/topic/71767
and some of you may be interested...
Well, the goal is that each category displays only its own posts and not those of its child categories.
here you go:
(this in WP v.2.0.4, line numbers may change in further versions)
just insert // at the very beginning of these lines - or destroy them:
$whichcat .= get_category_children($cat_array, ' '.$andor.' category_id '.$eq.' ');
$whichcat .= get_category_children($cat_array[$i], ' '.$andor.' category_id '.$eq.' ');
$whichcat .= get_category_children($q['cat'], " OR category_id = ");
You're done! Code is poetry, as they say!