add this line of code to main.css
Code:
div.subcategories img {
border: medium solid #CCCCCC;
padding-top: 3px;
padding-right: 3px;
padding-bottom: 3px;
padding-left: 3px;
}
that should be it. The only problem would be if 4.1.10 is set up differently... if so provide me with a link to your url and i'll be glad to help you.