Scene trigger going into Disarmed State runs constantly

I have an AD2USB and Vista 20p.

I am trying to create a scene that fires when the alarm is switched into a disarmed state.

My Vera scene has a trigger set as follows:

Device Trigger
Vista Part1 is DISARMED

For a test, I had it send me a notification when the scene is fired. The alarm is currently in a disarmed state. I immediately got 20 notifications, which is the quota.

Why does it fire the scene repeatedly, instead of only firing when the alarm goes into the disarmed state?