Hi all, I have a problem with my iMac 24" and I wonder if anyone heard about that. sometimes my screen has kind of flashes (it is seems like someone play with the brightness buttons). I googled "iMac screen problems" and I found that many people have other screen problem (a permanent gray corners on the top), this is not the problem that I have. so if someone know something... it will be great to hear/get feedback ! Thanks !!!