i have a problem with number of article in subcategories and categories...

example:
main categorie
-subcat1
--subcat2 -> 4 subcategories...
---subcat1 -> 3 Article
---subcat2 -> 3 Article
---subcat3 -> 3 Article
---subcat4 -> 3 Article
--subcat3 -> 1 Article
---subcat1 -> 3 Article
---subcat2 -> 3 Article
---subcat3 -> 3 Article
---subcat4 -> 3 Article


Following i can see on the frontpage....

--subcat2 -> 0 Article
---subcat1 -> 3 Article
---subcat2 -> 5 Article
---subcat3 -> 7 Article
---subcat4 -> 9 Article


here the numbers of article are wrong .. but why?

can nobody help?