The plugin doens’t seem to work, images are all stacked each other.
Open the console of the browser (F12) and refresh the page, look if there are errors in console, if so you should look at the source of the page and count how many times jQuery is included in the page. Sometimes other plugins or themes don’t include jQuery in the right way, and that can be the cause of the problem.
If you find jQuery included twice or more, than try to switch to the default theme, if this solves the problem, then you should ask the author of the theme to fix the issue. Reference: http://digwp.com/2009/06/including-jquery-in-wordpress-the-right-way/