i will log a bug about the error message on adding a file up,load field.
to get the file upload to work, the forms encoding type must be set to multipart/form-data
<form class="Basic_Default" id="Registration_Basic_Default" name="Registration_Basic_Default" method="post" action="<?php echo (htmlentities($_SERVER["PHP_SELF"]));?><?php echo(isset($_SERVER['QUERY_STRING'])?"?".str_replace("<","%3C",str_replace(">","%3E", str_replace('"',"%22", $_SERVER['QUERY_STRING']))):""); ?>">
to:
<form action="<?php echo (htmlentities($_SERVER["PHP_SELF"]));?><?php echo(isset($_SERVER['QUERY_STRING'])?"?".str_replace("<","%3C",str_replace(">","%3E", str_replace('"',"%22", $_SERVER['QUERY_STRING']))):""); ?>" method="post" enctype="multipart/form-data" name="Registration_Basic_Default" class="Basic_Default" id="Registration_Basic_Default">