jQuery .position() strangeness while using CSS3 rotate attribute

I'm getting absolutely positioned rotated elements position with jQuery .position() method, then setting position-related attributes (top, left) with jQuery .css(pos), where pos is the data returned by .position(). I think it'll leave the element in it's place, but elements position is changing.

How can I use set rotated elements position, so that it'll be placed as expected? Maybe there is a coefficient depended on angle that changes position?

I'm testing in Google Chrome v.9, Windows XP.

HTML

CSS

#container {
    position: relative;   
    border: 1px solid #999;
    padding: 5px;
    height: 300px;
    width:300px;
}    
#element {
    position: absolute;
    top:50px;
    left: 60px;
    width: auto;
    border: 1px solid #999;
    padding: 5px;
    -webkit-transform: rotate(45deg);
    -moz-transform: rotate(45deg);
}

JS

$(document).ready(function(){
    var $el = $('#element'),
    // getting position    
        pos = $el.position();
    alert(pos.left + '/' + pos.top);
    // alerts 37/11

    // setting css position attributes equal to pos
    $el.css(pos);
    // re-getting position
    pos = $el.position();
    alert(pos.left + '/' + pos.top);
    // alerts 14/-28
});    

View it http://jsfiddle.net/Antaranian/2gVL4/