UPDATE 19-12-09: I’ve made an adm file that you can use with Group Policy to configure the settings discussed below. You can download it here. It’s a classic template but works well enough.

UPDATE 17-12-09: Andre has rather helpfully sent me some information on an additional registry key. A number of people have been having problems with Communicator not downloading the address book properly or regularly since the July updates.

From what I can the issue occurs because of problems merging in compressed address book files. To turn off the use of the compressed address book files you can use a registry entry on the client. The registry key is:

NOTE: The below may wrap in your browser.

HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Communicator\GalUseCompactDeltaFile

It’s a DWORD value with the following potential values:

0: Do not use Compact Delta file

1: Use Compact Delta file (default)

2: Use Compact Delta file, but do not issue an LDAP query to retrieve the "Title" and "Office" attribute values from the Active Directory.

Any value other than these results in it defaulting to 1. If you’re having the non-updating Address Book issue then try deleting your local GalContacts.* files, quitting Communicator, entering the registry key above set to 0, and re-starting Communicator.

Thanks to Andre for passing on this information.

====================

Original Article

Most OCS techs are familiar with the process to regenerate the OCS Address Book. I wrote about it here:

Force Updating the OCS Address Book

There was also the trick of deleting the GalContacts.* on the client to force the downloading from the IIS share on the client. The behaviour on this seems to have changed - I think. I’m relatively sure the download used to happen quickly, whereas now with the later clients there’s a random delay of up to 60 minutes on the download.

This seems to be related to the July update if I read this KB correctly:

KB 972403

The scenario is that you delete the GalContacts files, re-start the Communicator client - and then wait. The Address Book is downloaded at a random time in that first hour.

There is a Group Policy/Registry Entry to control this behaviour. It’s useful if you’re testing/fault finding etc. The registry entry is as follows:

HKCU\Software\Policies\Microsoft\Communicator\GalDownloadInitialDelay

This is a DWORD value. If you set this to 0 (zero) and re-start Communicator your address book will be downloaded immediately.

I wouldn’t suggest generally deploying this setting as it can impact on bandwidth etc. however it’s useful to know for testing/fault-finding purposes.