Several times I have had my plasma screen turned on with a message displayed by the orbiter for hours. This static image, on top of the screensaver, could burn in the screen. Fortunately, aside from some temporary ghost images, no permanent effects for me.
But I do think it's preferable if the screensaver displays <b>on top of</b> the orbiter messages.
Also, somewhat related, I have had static DVD menus leave ghost images. (Kids watch movie, then leave everything on after movie ends...) The screen saver did not activate because the DVD was still "playing". Not sure how to fix that easily... We don't want a screensaver during actual movie playback