Outlook stops responding--Event log contains Application Hang Even

[R Chaf]

In our environment of about 120 computers, some clients are experiencing a
problem with Outlook 2003 SP2.

We use Exchange Server 2003 SP2 with SMTP connections to the clients.

The problem we're seeing is only on a small fraction of the clients. We
don't think it's a configuration issue since we use GPO to administer the
outlook settings.

The symptoms are:
Outlook stops repsonding.
2 instances of the application are seen in the task bar.
Sometimes 2 email notification instances are seen in the task bar.
Application not responding error messages are generated.
The event log will contain an entry for outlook:
Hanging application OUTLOOK.EXE, version 11.0.8000.0, hang module hungapp,
version 0.0.0.0, hang address 0x00000000.
Closing Outlook and restarting it works.
There aren't any Event Log entries on the Exchange server relating to this
issue.

The latest TechNet letter contains a reference to KB908521 which somewhat
relates to our situation, except that we are not using HTTP connections to
ES. I have not tried this yet.

Any help would be appreciated.