If you use a laptop and watch DVDs, this is a hint for you. If you stop watching the film and then close the screen, or just close the screen, when you open it up again, the viewer will be blue. Then it starts showing the film again. When you raise the volume or the brightness, the screen "expands" and then goes back to normal after two seconds. This is highly annoying. To avoid it, switch into full screen mode and then back out(via command-0 command-0). People who watch films in full screen mode don't have this problem.

[robg adds: I tried to confirm this one on a G3/500 iBook, but DVD Player just showed a black screen of normal proportions, and changing volume or brightness didn't cause it to expand to full screen. Can anyone confirm this behavior?]