What I did was pick out a scene that I would like to play as a demo. I have the DTS trailer on one disk, and two more disks that have 4-6 min scenes that I will use. What I do is play the DTS trailer first then the other scene as selected by the client.
So the sequence runs like this:
DVD Play
Light scene 3
DVD Play (you have to do it twice incase it was on screen saver)
27.750 sec Delay
Pause
Track Back
1 sec Delay
Discrete code for next disk
Delay (as long as I need for the scene)
Pause
Light scene 1
track back
1 sec delay
Discrete code for DTS disk
13 sec delay
pause
track back
So what essentially happens is that the player is always paused on the DTS demo untill it is played and then it jumps to the disk I want and begins playing at the point I left it last which is right at the begining of the scene I want to play. You have to add the 1 sec delay after pause, track back, before selecting the disk otherwise the disk will go back to the begining for some reason. I hope this can help some one else out there.