This problem occurs because Exchange System Attendant Service captures the change and updates the parent address list when you change the name of the parent address list. However, the child address list is not updated.
To resolve this issue, install the following update rollup:
2509911 Description of Update Rollup 4 for Exchange Server 2007 Service Pack 3
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about the Set-Mailbox cmdlet, visit the following Microsoft website: