Index: userplus.module
===================================================================
--- userplus.module	(revision 43)
+++ userplus.module	(working copy)
@@ -274,6 +274,7 @@
       else {
         $users_added[] = $u['name'];
         $mails_added[] = $u['mail'];
+        $u['pass'] = $u['pass'] ? $u['pass'] : user_password(10);
       }
 
       watchdog('user', 'New user: %name %email.',