$(document).ready(function() {
    if ($.browser.msie && parseInt(jQuery.browser.version, 10) <= 6) {
        $('div.menuitem').hover(
            function() {
                $(this).css({'background-image' : "url('/media/images/base/button-over.gif')"});
            },
            function() {
                $(this).css({'background-image' : "url('/media/images/base/button.gif')"});
            }
        );
    }
});