When the following conditions are all true in a Microsoft Exchange Server 2010 environment, the group members in the address list are not sorted by display name.
- Outlook is running in the cached mode.
- Offline address book (OAB) and hierarchical address book (HAB) are used.
- SeniorityIndex data is not deployed in HAB.
- The version of Outlook is not Japanese, or is Japanese with the DisableGALPhonetic registry turned on.