This is probably a stupid question, but I still can't figure it out (unlike most things OS X). I noticed that when I upgraded my refurb PB from panther to tiger, that the DVD playback and presentation options went away. I've set the screen never to go to sleep, but it still dims after a few minutes. What settings do you use on your 'Book? Why did Apple change this? PS. Did a quick search, found nothing. Please redirect me if this is old news.