Nivo slider - jquery - Not sliding evenly

Question

Hi all,

I was wondering if someone could shed some light on why my Nivo-Slider is so laggy??

It skips from 2nd to 3rd image quicker than normal, then takes a while to get back to the first image. There are only 3 images in this slider.

www.some-things.net is the address, and the slider is on the homepage.

It's particularly bad in firefox compared to chrome.

Here is the code that defines the slider. Maybe some of the rules are canceling each other out?

   <!-- SLIDER SETTINGS -->
   <script type="text/javascript">
        $(window).load(function() {
            $('#slider').nivoSlider({
                effect:'fade', //Specify sets like: 'fold,fade,sliceDown'
                slices:15,
                animSpeed:500,
                pauseTime:4000,
                startSlide:0, //Set starting Slide (0 index)
                directionNav:true, //Next & Prev
                directionNavHide:true, //Only show on hover
                controlNav:false, //1,2,3... for navigation - true
                controlNavThumbs:false, //Use thumbnails for Control Nav
                controlNavThumbsFromRel:false, //Use image rel for thumbs
                controlNavThumbsSearch: '.jpg', //Replace this with...
                controlNavThumbsReplace: '_thumb.jpg', //...this in thumb Image src
                keyboardNav:true, //Use left & right arrows
                pauseOnHover:true, //Stop animation while hovering
                manualAdvance:false, //Force manual transitions
                captionOpacity:0.8, //Universal caption opacity
                beforeChange: function(){},
                afterChange: function(){},
                slideshowEnd: function(){} //Triggers after all slides have been shown
            });
        });
        </script>