Resolution
Lotus Notes with Domino Authentication allows Directory Services Integration to be used, as well. Lotus Notes does insist that the user IDs are consistent in Domino/Lotus Notes and the Directory Services Integration performed.
Lotus Notes authenticates with MeetingPlace if the MeetingPlace ID and the Notes ID are the same. In this case, the web page is automatically entered when the Attend link is clicked from Lotus Notes. If MeetingPlace is integrated with the Active Directory (AD), the AD user ID must match the Lotus Notes user IDs.