Sorry for the delay, and thank you again for your reply.
Following your advice, I was able to monitor the change between Pending and Tracking, but I simply used Screen.fullScreen = false/true, since I can’t make your solution with ShowCurrentWindows work correctly on my laptop (it doesn’t re-focus on the game windows). But it’s not a big deal at all actually, the point was to automate the system without any problem nor asking the player for futher manipulation, and it works good now.
I made a topic for the game the team and I are working on : http://developer.tobii.com/community/forums/topic/grab-your-eyes/