IE8 Opacity Fade Bug: MooTools

If a child has relative positioning when the parent fades the child doesn't animate.

HTML

<button id="in">toggleIn</button>
<button id="out">toggleOut</button>
<hr/>
<p id="toggle_me">
    <a id="relative">position: relative</a>
    <a id="static">position: static</a>    
</p>

CSS

#toggle_me{
    display:inline-block;
} 
#relative {
    position: relative;
    display:inline-block;
    background:#fff;
}

JavaScript

$('#in').bind('click',function(){
    $('#toggle_me').fadeIn('slow',function() {
        if(this.style.removeAttribute){
        this.style.removeAttribute('filter');
        }
    });
});
$('#out').bind('click',function(){
    $('#toggle_me').fadeOut('slow');
});