Ok, this maybe be a dumb question.... I have just recieved my first PJ (Z3) last friday. We are using it for films and gaming. It has been a great hit with my son and he has been using it alot over the past few days. He mostly uses it for gaming and as such tends to use it for short periods throughout the day. I have been encouraging him to switch it off when he is not using it to preserve the bulb life, however, this probably means it is switched on and off at least half a dozen times a day. I remember reading somewhere on a thread the most of the damage caused to a bulb is during power up and power down. So, is it better for example to leave the project on for say a couple of hours when he may be only using it for less than half that time, OR is it better to turn it on and off several times during that same period?