It looks like the penultimate answer here solves the problem. I needed to fix this on a task we were doing on an outlook plugin at my workspace.
http://social.msdn.microsoft.com/Forums/en/vsto/thread/801e4980-a652-4705-9903-182c1a7dbfa5
> On Thursday, June 14, 2007 7:17 AM Tim Radford wrote:
> In my customised appointment inspector page I need to be able to access the
> Required Attendees list. However, this is not populated until the user has
> visited the "Scheduling" page .
>
> Can you tell me how to force this list to be populated without the user
> having to take any action?
>
> Thanks
> Tim