Modularity Lite – Align Center (slideshow)

I have posted this same question before, but I did not receive any help. Trying again.

I have the following piece of code in my style.css:

/* ************************ SLIDESHOW ********************************/
ul#portfolio {padding:0;list-style:none;margin:0 0 1em;overflow:hidden;max-height:590px;}
ul#portfolio li {list-style:none;padding:0;}
ul#portfolio li h4 {margin: 0 0 .5em 0;text-transform:uppercase;padding:0 16px;}
ul#portfolio li img {max-width:950px;text-align:center;margin:0;image-align:center;}

Although I set my images on the slideshow to align center, they are still aligning to the left.
Can someone help me?

The page is http://www.DaCostaChocolates.com

Thank you.