Subcategories without an equivalent menuitem have a wrong url query or the
routing do not work.

They are jump always back to Home and all Module assignmens are lost.

Test Instructions:

1. Install Joomla without example contents.
2. Create Categories: Maincategory->Subcategory1->Subcategory2.
3. Crate an test article and assign in Subcategory2.
4. Create a menu item with type 'Category List' and link to 'Maincategory'.
5. Go to the frontend
6. Click on the new menu item (all ok here, the menu item is aktive)
7. Click through the subcategories (the active menu jumps to Home!)

JoomlaCode Tracker Item: http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=29840