mooflow overlapping issue

Hi, I have a website that uses mooflow for image gallery. everything works just fine, except one. Please click bottom link [login to view URL] when you click right arrow, everything works fine. when you click left arrow on the slider, you will notice that the image becomes front at the end of emotion. I would like to remove delay when you click left arrow. I guess this is a z-index issue, but I can't find it on the source code. my budget is $30 thanks.