"Disallowed Key Characters" for HTML content - even using $_POST?!

[eluser]mattpointblank[/eluser]
That sort of code works for me, but in my ajax function, it works like this:

Code:

$('#sendPreview').bind('click', function(){
        
                title = $('#title').val();
        html = $('#content').val();
         email = $('#email').val();

        $.ajax({
            type: "POST",
            url: "<?php echo site_url(); ?>/newsletter/sendPreview",
            data: "title="+title+"&html;="+html+"&email;="+email,
            success: function(msg){
                //alert('The preview email was sent!');
                alert(msg);
            }
         });
     });

Eg, my script posts to a webpage and sends data, which is when it encounters CI's $_POST filtering.