Nobody has this issue? I have it on my laptop and desktop (both use the fglrx packages from livna).
It turns out it's not the changing of options in mplayer that stops the problem, it's starting two instances of mplayer simultainiously.
- start mplayer: 1 second black screen
- stop mplayer: 1 second black screen
- start a second instance of mplayer with the first still open: no problems
Now I can close all instances of mplayer, and start/stop them without the black screen. When I leave my PC for like 15 minutes, come back and try again: 1 second black screen.
I'm quite lost on where to look for a solution, because I've no idea what the source of the problem is. (the livna driver, xorg, mplayer, codec)