Index: tellafriend.module
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/tellafriend/tellafriend.module,v
retrieving revision 1.17
diff -u -p -r1.17 tellafriend.module
--- tellafriend.module	25 Dec 2008 22:05:48 -0000	1.17
+++ tellafriend.module	31 Dec 2008 15:45:30 -0000
@@ -450,7 +450,7 @@ function tellafriend_mail($key, &$messag
   $message['from'] .= $params['from'];
   $message['subject'] = $params['subject'];
   $message['body']    = $params['body'];
-  $message['headers'] = array_merge($message['headers'], $params['headers']);
+  $message['headers'] = array_merge($message['headers'], isset($params['headers']) ? $params['headers'] : array());
   $message['headers']['MIME-Version'] = '1.0';
   $message['headers']['Content-Type'] = 'text/html; charset=utf-8';  
 }