Occasionally, participants will get 90% of the way through the experiment, and MediaLab will exit after the 2nd to last task. I can't figure it out - especially since it doesn't always happen. When the experiment simply ends, no data are being recorded. I have watched participants for whom the program has exited, as it happens. The task after which it exits is a timed task (3 minutes). The dialogue box comes up to tell them time has elapsed, they press "ok" and the program exits.