From what I can see, you are setting each parent element to have a width of 69px, whilst each child image is 180px wide. This will cause overlapping, as the size of the image does not affect it's parent size.
applying these rule fixed the problem for me:
.es-carousel ul{
width: auto;
}
.es-carousel ul li {
width: 180px;
}
ensure you remove the 'width:69px' from each li element, too.