daslex,
М.б. грузить 3.html не в div, а в iframe?
Например, так ( index.html)
<head>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.0/jquery.min.js"></script>
<script>
$(document).ready(function(){
$('input[name=sw]').click(function(){
var v = ($(this).val());
console.log(v);
if(v === 'one'){
$('#one').show();
$('#two').hide();
$('#three').hide();
}
else if(v === 'two'){
$('#one').hide();
$('#two').show();
$('#three').hide();
}
else if(v === 'three'){
$('#one').hide();
$('#two').hide();
$('#three').show();
$(document).ready(function(){
$("#three").attr("src","3.html");
});
}
})
})
</script>
<style>
.none{
display:none;
}
</style>
</head>
<body>
<input type="radio" name="sw" value="one" id="x1"><label for="x1">1</label>
<input type="radio" name="sw" value="two" id="x2"><label for="x2">2</label>
<input type="radio" name="sw" value="three" id="x3"><label for="x3">3</label>
<div id="one" class="none"></div>
<div id="two" class="none"></div>
<iframe id="three" class="none" ></iframe>
</body>