try adding the following code at line 1 of the results page:
<?php
if($_SERVER["REQUEST_METHOD"] == "POST") {
foreach($_POST as $key => $val) {
if(is_array($_POST[$key])) $_POST[$key] = implode(", ", $_POST[$key]);
}
}
?>
if you continue to have a problem, please post a link where I can test this, and compress the search and results page to a zip archive and attach the zip file to your reply.