jquery animate background-position firefox

I got this background image slider thing working in chrome and safari, but it doesnt do anything in firefox. any help?

$(function(){
    var image= ".main-content";
    var button_left= "#button_left";
    var button_right= "#button_right";
    var animation= "easeOutQuint";
    var time= 800;
    var jump= 800;
    var action= 0;

    $(button_left).click(function(){
        right();
    });
    $(button_right).click(function(){
        left();
    });
    $(document).keydown(function(event){
        if(event.keyCode == '37'){
            right();
        }
    });
    $(document).keydown(function(event){
        if(event.keyCode == '39'){
            left();
        }
    });
    function left(){
        if(action == 0){
            action= 1;
            $(image).animate({backgroundPositionX: '-='+jump+'px'}, {duration: time, easing: animation});
            setTimeout(anim, time);
        }

    }
    function right(){
        if(action == 0){
            action= 1;
            $(image).animate({backgroundPositionX: '+='+jump+'px'}, {duration: time, easing: animation});
            setTimeout(anim, time);
        }
    }
    function anim(){
        action= 0;
    }
}); 

I also tried this but it also does nothing

$(image).animate({backgroundPosition: '500px 0px'}, 800);

The version above doesn't work with jQuery 1.6.1. This one does.

(function($) {
if(!document.defaultView || !document.defaultView.getComputedStyle){
    var oldCurCSS = jQuery.curCSS;
    jQuery.curCSS = function(elem, name, force){
        if(name === 'background-position'){
            name = 'backgroundPosition';
        }
        if(name !== 'backgroundPosition' || !elem.currentStyle || elem.currentStyle[ name ]){
            return oldCurCSS.apply(this, arguments);
        }
        var style = elem.style;
        if ( !force && style && style[ name ] ){
            return style[ name ];
        }
        return oldCurCSS(elem, 'backgroundPositionX', force) +' '+ oldCurCSS(elem, 'backgroundPositionY', force);
    };
}

var oldAnim = $.fn.animate;
$.fn.animate = function(prop){
    if('background-position' in prop){
        prop.backgroundPosition = prop['background-position'];
        delete prop['background-position'];
    }
    if('backgroundPosition' in prop){
        prop.backgroundPosition = '('+ prop.backgroundPosition + ')';
    }
    return oldAnim.apply(this, arguments);
};

function toArray(strg){
    strg = strg.replace(/left|top/g,'0px');
    strg = strg.replace(/center/g,'50%');
    strg = strg.replace(/right|bottom/g,'100%');
    strg = strg.replace(/([0-9\.]+)(\s|\)|$)/g,"$1px$2");
    var res = strg.match(/(-?[0-9\.]+)(px|\%|em|pt)\s(-?[0-9\.]+)(px|\%|em|pt)/);
    return [parseFloat(res[1],10),res[2],parseFloat(res[3],10),res[4]];
}

$.fx.step.backgroundPosition = function(fx) {
    if (!fx.bgPosReady) {
        var start = $.curCSS(fx.elem,'backgroundPosition');

        if(!start){//FF2 no inline-style fallback
            start = '0px 0px';
        }

        start = toArray(start);

        fx.start = [start[0],start[2]];

        var end = toArray(fx.end);
        fx.end = [end[0],end[2]];

        fx.unit = [end[1],end[3]];
        fx.bgPosReady = true;
    }

    var nowPosX = [];
    nowPosX[0] = ((fx.end[0] - fx.start[0]) * fx.pos) + fx.start[0] + fx.unit[0];
    nowPosX[1] = ((fx.end[1] - fx.start[1]) * fx.pos) + fx.start[1] + fx.unit[1];
    fx.elem.style.backgroundPosition = nowPosX[0]+' '+nowPosX[1];
};
})(jQuery);

The code posted by magiconair no longer works with jQuery 1.8. Here is a patched version that doesn't use the depreciated $.curCSS() method.

(function($) {
if(!document.defaultView || !document.defaultView.getComputedStyle){
    var oldCSS = jQuery.css;
    jQuery.css = function(elem, name, force){
        if(name === 'background-position'){
            name = 'backgroundPosition';
        }
        if(name !== 'backgroundPosition' || !elem.currentStyle || elem.currentStyle[ name ]){
            return oldCSS.apply(this, arguments);
        }
        var style = elem.style;
        if ( !force && style && style[ name ] ){
            return style[ name ];
        }
        return oldCSS(elem, 'backgroundPositionX', force) +' '+ oldCSS(elem, 'backgroundPositionY', force);
    };
}

var oldAnim = $.fn.animate;
$.fn.animate = function(prop){
    if('background-position' in prop){
        prop.backgroundPosition = prop['background-position'];
        delete prop['background-position'];
    }
    if('backgroundPosition' in prop){
        prop.backgroundPosition = '('+ prop.backgroundPosition + ')';
    }
    return oldAnim.apply(this, arguments);
};

function toArray(strg){
    strg = strg.replace(/left|top/g,'0px');
    strg = strg.replace(/right|bottom/g,'100%');
    strg = strg.replace(/([0-9\.]+)(\s|\)|$)/g,"$1px$2");
    var res = strg.match(/(-?[0-9\.]+)(px|\%|em|pt)\s(-?[0-9\.]+)(px|\%|em|pt)/);
    return [parseFloat(res[1],10),res[2],parseFloat(res[3],10),res[4]];
}

$.fx.step.backgroundPosition = function(fx) {
    if (!fx.bgPosReady) {
        var start = $.css(fx.elem,'backgroundPosition');

        if(!start){//FF2 no inline-style fallback
            start = '0px 0px';
        }

        start = toArray(start);

        fx.start = [start[0],start[2]];

        var end = toArray(fx.end);
        fx.end = [end[0],end[2]];

        fx.unit = [end[1],end[3]];
        fx.bgPosReady = true;
    }

    var nowPosX = [];
    nowPosX[0] = ((fx.end[0] - fx.start[0]) * fx.pos) + fx.start[0] + fx.unit[0];
    nowPosX[1] = ((fx.end[1] - fx.start[1]) * fx.pos) + fx.start[1] + fx.unit[1];
    fx.elem.style.backgroundPosition = nowPosX[0]+' '+nowPosX[1];
};
})(jQuery);

This code works well for me with jQuery 1.8.1 and Firefox, i had some issues getting Prydie's example to work:

http://nelsonwells.net/2012/08/using-bgpos-js-with-jquery-18/

/**
 * @author Alexander Farkas
 * v. 1.02
 *
 * Edited by Nelson Wells for jQuery 1.8 compatibility
 */
(function($) {
    $.extend($.fx.step,{
        backgroundPosition: function(fx) {
            if (fx.pos === 0 && typeof fx.end == 'string') {
                var start = $.css(fx.elem,'backgroundPosition');
                start = toArray(start);
                fx.start = [start[0],start[2]];
                var end = toArray(fx.end);
                fx.end = [end[0],end[2]];
                fx.unit = [end[1],end[3]];
            }
            var nowPosX = [];
            nowPosX[0] = ((fx.end[0] - fx.start[0]) * fx.pos) + fx.start[0] + fx.unit[0];
            nowPosX[1] = ((fx.end[1] - fx.start[1]) * fx.pos) + fx.start[1] + fx.unit[1];
            fx.elem.style.backgroundPosition = nowPosX[0]+' '+nowPosX[1];

            function toArray(strg){
                strg = strg.replace(/left|top/g,'0px');
                strg = strg.replace(/right|bottom/g,'100%');
                strg = strg.replace(/([0-9\.]+)(\s|\)|$)/g,"$1px$2");
                var res = strg.match(/(-?[0-9\.]+)(px|\%|em|pt)\s(-?[0-9\.]+)(px|\%|em|pt)/);
                return [parseFloat(res[1],10),res[2],parseFloat(res[3],10),res[4]];
            }
        }
    });
})(jQuery);

here try this for background animation

(function($) {
    if (!document.defaultView || !document.defaultView.getComputedStyle) {
        var oldCurCSS = jQuery.curCSS;
        jQuery.curCSS = function(elem, name, force) {
            if (name === 'background-position') {
                name = 'backgroundPosition';
            }
            if (name !== 'backgroundPosition' || !elem.currentStyle || elem.currentStyle[name]) {
                return oldCurCSS.apply(this, arguments);
            }
            var style = elem.style;
            if (!force && style && style[name]) {
                return style[name];
            }
            return oldCurCSS(elem, 'backgroundPositionX', force) + ' ' + oldCurCSS(elem, 'backgroundPositionY', force);
        };
    }
    var oldAnim = $.fn.animate;
    $.fn.animate = function(prop) {
        if ('background-position' in prop) {
            prop.backgroundPosition = prop['background-position'];
            delete prop['background-position'];
        }
        if ('backgroundPosition' in prop) {
            prop.backgroundPosition = '(' + prop.backgroundPosition;
        }
        return oldAnim.apply(this, arguments);
    };

    function toArray(strg) {
        strg = strg.replace(/left|top/g, '0px');
        strg = strg.replace(/right|bottom/g, '100%');
        strg = strg.replace(/([0-9\.]+)(\s|\)|$)/g, "$1px$2");
        var res = strg.match(/(-?[0-9\.]+)(px|\%|em|pt)\s(-?[0-9\.]+)(px|\%|em|pt)/);
        return [parseFloat(res[1], 10), res[2], parseFloat(res[3], 10), res[4]];
    }
    $.fx.step.backgroundPosition = function(fx) {
        if (!fx.bgPosReady) {
            var start = $.curCSS(fx.elem, 'backgroundPosition');

            if (!start) { //FF2 no inline-style fallback
                start = '0px 0px';
            }
            start = toArray(start);
            fx.start = [start[0], start[2]];
            var end = toArray(fx.options.curAnim.backgroundPosition);
            fx.end = [end[0], end[2]];
            fx.unit = [end[1], end[3]];
            fx.bgPosReady = true;
        }
        //return;
        var nowPosX = [];
        nowPosX[0] = ((fx.end[0] - fx.start[0]) * fx.pos) + fx.start[0] + fx.unit[0];
        nowPosX[1] = ((fx.end[1] - fx.start[1]) * fx.pos) + fx.start[1] + fx.unit[1];
        fx.elem.style.backgroundPosition = nowPosX[0] + ' ' + nowPosX[1];
    };
})(jQuery);

Call to it like this,

$(this).animate({
    backgroundPosition: '0 0'
})