Hi all, I just got the screen where everything goes grey, then you get a box that pops up saying you need to restart your computer in about 4 languages. So i restarted it like it said and everything seems ok. Does anyone know why my mac has done this, and do you if this screen means it has permanent damage? The iMac is a 2.4ghz core 2 duo, 2008. Thankyou for your time.