Main category shows post of sub-categories

Hi
I’ve a problem that I hope you can help me with.
I’ve four main categories each contains a number of sub-categories, for example:
Diary
*Protected Diary
*Diary with Pictures

So “Diary” is my main category in which I publish most of my diary notes. When I add pictures to my notes I publish it in the sub-category “Diary with Pictures”.
Now to my “problem”, when I click the link to my Diary-category I get all the posts in the main category and all the posts in the two sub categories when I just want the posts filed under the main category.
Let’s say I have 9 posts in the “Diary” category, 5 posts in the “Protected Diary” category and 3 posts in the “Diary with Pictures” category. So when I click to show posts in the “Diary” category I just want to show those 9 posts, no other posts.
How do I do that?

I use the Sidebar Widgets and the template-tag: wp_list_cats(“sort_column=name&optioncount=0&hierarchical=1”);
I’ve just upgraded my WordPress to 2.0.6
And yes I tick the right boxes when I write my posts.

Thanks for your help!
Nina