Index: privatemsg.module
===================================================================
RCS file: /cvs/drupal/contributions/modules/privatemsg/privatemsg.module,v
retrieving revision 1.70.2.30.2.91.2.73
diff -u -p -r1.70.2.30.2.91.2.73 privatemsg.module
--- privatemsg.module	10 Oct 2009 08:04:48 -0000	1.70.2.30.2.91.2.73
+++ privatemsg.module	10 Oct 2009 17:45:22 -0000
@@ -1646,7 +1646,7 @@ function _privatemsg_send($message) {
     }
   }
 
-  if (isset($message['read_all'])) {
+  if (isset($message['read_all']) && $message['read_all']) {
     // The message was sent in read all mode, add the author as recipient to all
     // existing messages.
     $query_messages = _privatemsg_assemble_query('messages', array($message['thread_id']), NULL);