If someone adds the birthday date to a contact via Outlook, Outlook creates a
calendar series which doesn't get changed or doubled if you change anything
at the contact (how it should be).

If you do the same via VBA via the
Microsoft.Office.Interop.Outlook.Application Namespace every "myItem.Save()"
of an contact item results in a new calendar series.

Any ideas why and how to prevent this behavior?
Thanks Thomas