Breadcrumbs don't show parent category

Hi,

There is a post with a child category.
When I open it, breadcrumbs don’t show the parent category only the child. It would be useful to be able to see the whole hierarchy.
More confusing, when I open the parent category list and if that post is the first, breadcrumbs show the child category instead of the clicked one which is wrong.
Can you help me with this?
Thanks
Istvan