The script below assumes that the content area of your site is wrapped in a div tag with an id of content. The first portion eliminates all ® marks from input values, as superscript tags seem to negatively affect IE.
$(document).ready(function() {
$('#content form input').each(function() {
$(this).val($(this).val().replace(/®/gi,''));
});
$("#content").html(
$("#content").html().replace(/®/gi, '<sup>®</sup>')
.replace(/®/gi, '<sup>®</sup>');
);
});