It appears that the plugin is hooking into content display (and excerpt display) to inject the following code:
<script type="text/javascript">
jQuery(document).ready(function($) {
$('#add_guests').click(function(){
$('.add_one').append('<div class=\"guest_blank\">First Name: <input type=\"text\" name=\"guestfirst[]\" style=\"width:30%\" /> Last Name: <input type=\"text\" name=\"guestlast[]\" style=\"width:30%\"/><input type=\"hidden\" name=\"guestid[]\" value=\"0\" /></div>');});
});
</script>which means that the add_guests object is bound to several times if multiple posts are displayed on a page. The code should be added to the page using the wp_footer hook, and probably should be added only if the post type being displayed is an RSVPmaker post type.
Just my thoughts -- the script is showing up everywhere in the HTML source code.
