My Powerbook had the infamous white spots and the dealer I bought it from arranged with Apple to have the screen replaced. I suddenly got a call saying that a technician could come and do it at my home today. When the technician arrived, he found that he didn't have the right sized screwdriver and left to get more tools...but then phoned to say he would return tomorrow instead. How can a technician not even have the necessary screw driver?! It certainly doesn't instill much confidence. Anyway, is there now a conclusive finding as to what causes these spots? Is the fix likely to be permanent?