Blocks

This is a little restrictive.
We are developing a "Personal courses space" and when we make category an subcategory levels (for organization of elements), appear one level o page (category an subcategory) where all the blocs dissapear. How can make to put bloks o those pages?

If the user clics on a course link thera are no problem, buen if he clic on a category or subcategoryu level, the interface will look diferent for him.

Thanks in advance.

David