This is a patch to the documentation that warns users to sync permissions for twin menu items as a work around to get the desired result. Refer to http://drupal.org/node/109463 for case.
This is 3 years old... I'm closing it. Hopefully you'll be able to upgrade to 6.x and get that resolved. There are no 5.x maintainers.
Drupal is a registered trademark of Dries Buytaert.