Confusing behavior occurs when inviting a user to a conference when that user does not have the correct permissions to join the conference.
It appears as if you invited the user, when in fact, the user never received the invitation.
Access permission changes do not take effect in conference rooms.
If you change access permissions for users already in a conference room, the changes do not take effect until you relaunch the conference room window.
Workaround: Close and relaunch the conference room window to update access permissions.
You cannot enter the same conference room from multiple concurrent Instant Messaging sessions.