Revi algumas postagens neste site sobre esse problema com o Nivo Slider. Verifiquei minhas vírgulas no javascript e parece certo para mim:

<script type="text/javascript">
$(window).load(function() {
    $('#slider').nivoSlider({
        effect:'fade', 
        slices:15,
        animSpeed:500, 
        pauseTime:4000,
        startSlide:0,
        directionNav:false, 
        directionNavHide:false, 
        controlNav:true,
        controlNavThumbs:false, 
        controlNavThumbsFromRel:false, 
        controlNavThumbsSearch: '.jpg', 
        controlNavThumbsReplace: '_thumb.jpg', 
        keyboardNav:true,
        pauseOnHover:true, 
        manualAdvance:false, 
        captionOpacity:0.9, 
        beforeChange: function(){},
        afterChange: function(){},
        slideshowEnd: function(){}, 
        lastSlide: function(){}, 
        afterLoad: function(){} 
    });
});
</script>

Aqui está o html que ele está fazendo referência. O caminho da pasta parece estar correto (afinal, está funcionando em outros navegadores!):

<div id="slider_wrapper">
        <div id="slider">
            <img src="/CoVPrototype/images/nivoslider/_img1.jpg" alt="" title="Discover City Parks" />
            <img src="/CoVPrototype/images/nivoslider/_img2.jpg" alt="" title="Enjoy Our Beautiful City" />
            <img src="/CoVPrototype/images/nivoslider/_img3.jpg" alt="" title="This is an example of a caption" />
            <img src="/CoVPrototype/images/nivoslider/_img4.jpg" alt="" title="This is Our Home" />
            <img src="/CoVPrototype/images/nivoslider/_img5.jpg" alt="" title="Mild Tempuratures and Natural Beauty" />
        </div>
    </div>

e finalmente, aqui está o link para o javascript:

<script src="/CoVPrototype/js/jquery.nivo.slider.pack.js" type="text/javascript"></script>

Perdi meio dia tentando resolver esse problema! Espero que esta lista poderosa possa identificar o problema !!

Pensei em adicionar o css também, caso este pudesse ser o culpado de alguma forma:

#slider_wrapper {
    margin:0 auto;
    width:740px;
    height:360px;
}
#slider {
    width:738px; /* Change this to your images width */
    height:360px; /* Change this to your images height */
    background:url(/CoVPrototype/images/nivoslider/loading.gif) no-repeat 50% 50%;
    overflow:hidden;
    margin-top:25px;
    left:-96px;
    /*--Top right rounded corner--*/
    -moz-border-radius-topright: 5px;
    -khtml-border-radius-topright: 5px;
    -webkit-border-top-right-radius: 5px;
    /*--Top left rounded corner--*/
    -moz-border-radius-topleft: 5px;
    -khtml-border-radius-topleft: 5px;
    -webkit-border-top-left-radius: 5px;
    /*--Bottom right rounded corner--*/
    -moz-border-radius-bottomright: 5px;
    -khtml-border-radius-bottomright: 5px;
    -webkit-border-bottom-right-radius: 5px;
    /*--Bottom left rounded corner--*/
    -moz-border-radius-bottomleft: 5px;
    -khtml-border-radius-bottomleft: 5px;
    -webkit-border-bottom-left-radius: 5px;
}
#slider img {
    position:absolute;
    top:0px;
    left:0px;
    display:none;
}
#slider a {
    border:0;
    display:block;
}

.nivoSlider {
    position:relative;
}
.nivoSlider img {
    position:absolute;
    top:0px;
    left:0px;
}
/* If an image is wrapped in a link */
.nivoSlider a.nivo-imageLink {
    position:absolute;
    top:0px;
    left:0px;
    width:100%;
    height:100%;
    border:0;
    padding:0;
    margin:0;
    z-index:60;
    display:block;
}
/* The slices in the Slider */
.nivo-slice {
    display:block;
    position:absolute;
    z-index:50;
    height:100%;
    /*--Top right rounded corner--*/
    -moz-border-radius-topright: 5px;
    -khtml-border-radius-topright: 5px;
    -webkit-border-top-right-radius: 5px;
    /*--Top left rounded corner--*/
    -moz-border-radius-topleft: 5px;
    -khtml-border-radius-topleft: 5px;
    -webkit-border-top-left-radius: 5px;
    /*--Bottom right rounded corner--*/
    -moz-border-radius-bottomright: 5px;
    -khtml-border-radius-bottomright: 5px;
    -webkit-border-bottom-right-radius: 5px;
    /*--Bottom left rounded corner--*/
    -moz-border-radius-bottomleft: 5px;
    -khtml-border-radius-bottomleft: 5px;
    -webkit-border-bottom-left-radius: 5px;
}
/* Caption styles */
.nivo-caption {
    position:absolute;
    left:0px;
    bottom:0px;
    background:#F1F0EB;
    color:#5D79A1;
    filter: alpha(opacity=90);
    -ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=90)";
 /* Overridden by captionOpacity setting */
    width:100%;
    z-index:89;
    height:32px;
    /*--Bottom right rounded corner--*/
    -moz-border-radius-bottomright: 5px;
    -khtml-border-radius-bottomright: 5px;
    -webkit-border-bottom-right-radius: 5px;
    /*--Bottom left rounded corner--*/
    -moz-border-radius-bottomleft: 5px;
    -khtml-border-radius-bottomleft: 5px;
    -webkit-border-bottom-left-radius: 5px;
}
.nivo-caption p {
    padding:8px 5px 5px 11px;
    margin:0;
    font-family:"Lucida Sans Unicode", "Lucida Grande", sans-serif;
    font-size:1.1em;
}
.nivo-caption a {
    display:inline !important;
}
.nivo-html-caption {
    display:none;
}