Caregory module hidden container function not working

Thanks Ramdak , that was a useful insight, but my issue is I want the end user who is posting content to be only offered a selection from two containers (section and topic), but not the third (articles) . I have enabled hidden container,but it still appears as an option to the end user under the categories section of the admin interface for the posting. I am using articles as a root parent so I had one place where all the content can be found , not for users, but for admin purposes .

I also have a second related issue . Ideally I would like to offer to users a first selection of sections (eg politics, business, sport) and then dependent on that choice then be offered the relevant topic choice to that section. So if a user for example selects sport they would then be presented with say only football, athletics, swimming etc, and not all the other topics from other sections such as equities, markets, federal politics etc.

The only posting on this I have found is at http://drupal.org/node/74747 . Followed the six steps slavishly, but sadly when I got to step six I was unable to get category and active select modules to offer me a choice of having the node belong in one container (in that example Breed), but associated with a category from its distant parent container (in that example Cat or Horse)

My simple aim here is to allow users to post their content to a two tier structure Section X and then topic X1 or x2 or x3, Section Y and then topics y1,y2,or y3.

Any insights you or any one else has on this would be most welcomed.