If Outlook uses the search key to group, and the contact was moved between
folders (that would change the entry id under Exchange but not the search
key), this would be exactly the behavior that you see.

Dmitry Streblechenko (MVP)
http://www.dimastr.com/
OutlookSpy - Outlook, CDO
and MAPI Developer Tool

"Sue Mosher [MVP-Outlook]" wrote in message
...
Which means that if double-clicking the contact link produces a message that
the contact doesn't exist, something has been done to break the link. Just
changing the name of the contact would not break the link. In that case,
though, I wouldn't expect the task to show up on the Activities page of the
contact. Very puzzling to have two conflicting behaviors.

--
Sue Mosher, Outlook MVP
Author of Microsoft Outlook 2007 Programming:
Jumpstart for Power Users and Administrators
http://www.outlookcode.com/article.aspx?id=54


"Dmitry Streblechenko" wrote in message
...
Outlook stores contact display name (which can change), but also contact
entry id and search key (which do not change unless the contact is
recreated) for each link.

Dmitry Streblechenko (MVP)
http://www.dimastr.com/
OutlookSpy - Outlook, CDO
and MAPI Developer Tool

"Matt Williamson" wrote in message
...
The Links collection is the correct field. Each individual Link has an
Item property that returns a linked contact, if one exists.
What Outlook version are you working with?

Outlook 2003 Sp2. The problem is that the linked contact doesn't exist,
yet there has to be an identifier other than the Item.name, otherwise,
how
would Outlook know to group them correctly?

Example

I have a list of tasks for a contact going back for years. During that
time, the contact name has changed multiple times. If I click on the
contact field in one of the tasks that was linked prior to the name
changing, it gives me an error message about it not existing. How does
Outlook know to group that Task with that contact on the activity tab
after all of the name changes? There has to be some sort of GUID or
unique
identifier because it isn't the link.item.name any longer.