Index: messaging.module
===================================================================
--- messaging.module	(revision 624)
+++ messaging.module	(working copy)
@@ -452,7 +452,7 @@
   // Provides a hook for other modules to modify the message before sending  
   foreach (module_implements('message_alter') as $module) {
     $function = $module.'_message_alter';
-    $function($message, $info, $method);
+    $function(&$message, $info, $method);
   }
 
   // Renders subject and body applying filters in the process