To remove effect to rotate image, add this css to end of style.css file:
/* REMOVE EFFECT ROTATE IMAGE */
html #main-module-container ul li.product a .product-image-back {display:none !important;}
html #main-module-container ul li.product a:hover .product-image-front {transform:none !important;-moz-transform:none !important;-webkit-transform:none !important;}