I was able to solve this problem when making the suit doors in Minimicus. My solution was a little complex. The door is set to 'toggle'. Two trigger_multiples in front of the door, each with their own master, so that only one of them is active at a time. The one closest to the door is active initially. When the active one gets triggered, it targets a multimanager that opens (or closes) the door and switches the masters. The trigger_multiples are set far enough apart so that the player can't touch both of them at the same time. As long as you stay in the area near the door, it will stay open. It only closes when you leave the area and pass through the other trigger_multiple. If you set it up properly, the player can't mess it up no matter how he moves around. I used the same setup for the cricket sound in the basement of minimicus. When you get near the cricket, he shuts up. Then when you walk away, he starts chirping again. I would be willing to post an example map for the doors if anyone is interested.