[jQuery] Invalid argument jquery.min.1.3.2.js Code 0 IE7,IE8

[LuisFernando]

Check it out

HTML
<ul>
        <li>one</li>
        <li>two</li>
        <li>three</li>
        <li>four</li>
        <li>five</li>
</ul>

CSS

ul{
        display:block;
        overflow:hidden;
        padding:0px;
        margin:0px;
}
ul li{
        list-style-type:none;
        float:left;
        background-color:#666;
        margin-right:10px;
        position:relative;
        top:0px;
        padding:5px 10px;
}

JAVASCRIPT

        var menu_node           = null;
        var menu_lenght         = $("ul").children().length;
        var menu_elements       = $("ul").children();
        var total_widths        = 0;
        var speed                       = 1000;

        for(i=0;i<menu_lenght;i++){
                menu_node               = menu_elements[i];
                total_widths    += $(menu_node).outerWidth();
                total_widths    += parseInt($(menu_node).css("margin-left"),10);
                total_widths    += 
parseInt($(menu_node).css("margin-right"),10);
                $(menu_node).css({"left":"-"+total_widths+"px"});
        }
        for(i=0;i<menu_lenght;i++){
                menu_node = menu_elements[i];
                $(menu_node).animate({left:"0px"},speed);
        }

ERROR IN IE7 and IE8 :'(

Webpage error details

User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64;
Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR
3.0.30729; Media Center PC 6.0)
Timestamp: Mon, 23 Nov 2009 17:00:24 UTC

Message: Invalid argument.
Line: 12
Char: 12949
Code: 0
URI: http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js

ERROR LINE:

$(menu_node).css({"left":"-"+total_widths+"px"});


Tracing with the developer tool of IE8 i found
http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js or
either other jquery 1.3.2

1661: elem[ name ] = value;

Any suggestion?

Thanks....