Article ID: 976985
To preserve network bandwidth, Microsoft Office Communicator 2007 R2 downloads the new address book delta files instead of legacy delta files. In this scenario, the address book delta files merge with the local address book database. However, the address book delta files do not include the Title or Office attribute values. Therefore, Office Communicator 2007 R2 runs Lightweight Directory Access Protocol (LDAP) queries to obtain this information from a domain controller.
However, a NULL password is occasionally presented to the domain controller. In this scenario, the domain controller interprets this behavior as an invalid logon attempt. After a predefined number of invalid logon attempts, Windows user accounts are locked out.
To resolve this issue, apply the following update:
322756After you apply this update, OCS administrators can determine how their clients download address book delta files. To control how Office Communicator 2007 R2 users download address book delta files, use the following registry entry:
(https://support.microsoft.com/kb/322756/ )How to back up and restore the registry in Windows
HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Communicator\GalUseCompactDeltaFile (Type: DWORD)
Some possible values for this registry entry include the following:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Article ID: 976985 - Last Review: October 10, 2011 - Revision: 2.0