Index: privatemsg.module
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/privatemsg/privatemsg.module,v
retrieving revision 1.70.2.30.2.91.2.81
diff -u -p -r1.70.2.30.2.91.2.81 privatemsg.module
--- privatemsg.module	27 Oct 2009 11:31:34 -0000	1.70.2.30.2.91.2.81
+++ privatemsg.module	28 Oct 2009 17:28:05 -0000
@@ -1756,7 +1756,10 @@ function privatemsg_message_load_multipl
   $messages = array();
   while ($message = db_fetch_array($result)) {
     // Load author of message.
-    $message['author'] = user_load($message['author']);
+    if (!($message['author'] = user_load($message['author']))) {
+      // If user does not exist, load anonymous user.
+      $message['author'] = user_load(array('uid' => 0));
+    }
     $returned = module_invoke_all('privatemsg_message_load', $message);
     if (!empty($returned)) {
       $message = array_merge_recursive($returned, $message);