DW Focus category logo not always working

Hello,
I really don’t understand what exactly the problem might be… I have 6 categories with specific logos. The first 4 work just fine, but after this all categories have the same logo, even if I change that. The logo that keeps showing up is a category with sub-categories, maybe this is what chages the following setups ?
You can have a look at
http://www.revuepolitique.fr/refonte
Categories "economie", "international", "culture" and "la revue" work fine, no way to have the logo I want for "politique" and "vie du parlement", they show the slogo for "la revue".
Thanks for telling me what might be the problem.