jQuery core computes different "height" or "width" in IE8

In IE8 jQuery css returns padding differently with fractional em values.

by akatsuki

HTML

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.0/jquery.js"></script>
<div id="box1"></div>
<div id="box2"></div>

CSS

div { font-size:15px;width:500px; }
#box1 { padding:0.4em; } /* =6px */
#box2 { padding:0.5em; } /* =7.5px */

JavaScript

jQuery.each([ '#box1', '#box2' ], function (i, selector) {
    var box = $(selector);
    box.append('offsetWidth: ' + box[0].offsetWidth);
    box.append(', padding-left: ' + box.css('padding-left'));
    box.append(', width: ' + box.outerWidth());
});