On a recent Air Canada flight the flight attendant actually came on the PA to tell everyone that the in-flight entertainment system was being turned on for our use. She then proceeded to tell us to be sure we didn't push 4 of the buttons on the main screen or else the screen at your seat would crash and they would be unable to fix it in flight. I thought it strange that a computer entertainment system installed in an aircraft would be a "work in progress" instead of just installing a full-functional system. Among the buttons we were not to touch? Weather and Flight tracking...of course.