I had the same issue as missc23 and fixed it by using CSS Z-Index. no script.
Just change the class="{$key2}" by something like class="roll{$key2}"
So now in your product-list.css you add :
EDIT : doesnt work on search / manufacturer and block layered pages
IT ONLY WORKS IF YOU DON'T USE THE LAYERED NAVIGATION and still don't work on Search, Manufacturer,New products pages.
If you want to use the old product-list.tpl (the old that only shows 1 image) only for those pages, you can still use the #36 post's trick.
http://www.prestasho...post__p__951419