problem custom product miniature tpl

[Amir]

hello all,

i need help for a custom developement on the product.tpl file. i'm adding a custom png logo on each miniature picture with the following code :

    {if $product.category_default == "Produits AVS"}
      <img style="position:absolute; right: 1px; top: 1px;" src="img/certification-avs.png">
     {/if}

www.sovolailles.fr

it's work well on the first page "featured product" but only in the first page. That modifiation don't work on category's pages. 

What is wrong ? 

I tried all kind of relative path but still the same

Thanks you for your help.

Amir