Thanks, that did it
Thanks Eric,
When I applied session_write_close() that did it but there were two more instances of session_commit () that I also changed to session_write_close() on the confirm page and then one in the mail_php.php page.
I hope that is ok, as all emails appear to have gone through.
One more question though - Will upgrading my php to the latest version negatively impact any of my past pages when editing them is necessary?