[jQuery] the implementation of jQuery.boxModel

[jQuery] the implementation of jQuery.boxModel


in jq-1.2.5,
jQuery.boxModel = !jQuery.browser.msie || document.compatMode
== "CSS1Compat"
but in jq-1.3.2,
jQuery(function(){
        var div = document.createElement("div");
        div.style.width = div.style.paddingLeft = "1px";
        document.body.appendChild( div );
        jQuery.boxModel = jQuery.support.boxModel = div.offsetWidth === 2;
        document.body.removeChild( div ).style.display = 'none';
    });
I wanna know why the implementation of jQuery.boxModel changed?