Object of class stdClass could not be converted to string in

Module seems to work completely but in my Drupal log file I get.

Type php
Date Monday, March 17, 2008 - 3:39pm
User Anonymous
Location http://www.adoptionagencyratings.com/comment/reply/1330
Referrer http://www.adoptionagencyratings.com/christian-adoption-services-inc.htm
Message Object of class stdClass could not be converted to string in /hsphere/local/home/adoptionagencyratings.com/modules/comment_notify/comment_notify.module on line 279.
Severity error

For every email sent.

278 while ($alert = db_fetch_object($result)) {
279 if ($alert->mail != $comment_mail && !in_array($alert->mail, $sent_to) && $alert.uid != $comment->uid) {