I am working in version 1.9.2.4.
I have a problem with the add to cart button when I am not logged.
It does not appear in the category grid search but in the list view it does.
That happened with the single product view too.
I modified the file list.phtml from /app/design/frontend/royal/hijo/template/catalog/product
I remove the code but the problem still existing
if(Mage::getSingleton('customer/session')->isLoggedIn() && $total > 0)