With the disc in the drive click on edit then pick 'select main movie + ifos Or click in Tools>Settings>File Mode tab. Under 'on startup' pick main movie + ifos if you want to do the main movie only as your default setting.
multipost closed, have left this one open here - http://forums.afterdawn.com/thread_view.cfm/565109 Please be careful of the CAP LOCK as per that link also