this is really a pretty simple problem, it has to do with data persistence.
page one has a form element on it named "id", it posts to the callback.php page and filters the recordset when it is loaded.
the problem is that the form on callback.php does not post the id when it triggers UE to send the email.
the solution is to add a hidden element named "id" to the callback.php form that captures the value sent in from the initial page:
<input name="id" type="hidden" id="id" value="<?php echo((isset($_POST["id"]))?$_POST["id"]:"") ?>" />