Since I saw the announcement last night about 9.1 I've been playing with it trying to get mplayer to work with Xv.
I have a standard Ubuntu 8.10 setup, currently running 9.2beta(tried with 9.1 final too).
Mplayer and xine both show a blue screen. Xorg.conf is just standard again.
After trying for a while I get:
[VO_XV] Could not grab port 131.
[VO_XV] Could not find free Xvideo port - maybe another process is already
[VO_XV] using it. Close all video applications, and try again. If that does
[VO_XV] not help, see 'mplayer -vo help' for other (non-xv) video out drivers.
Error opening/initializing the selected video_out (-vo) device.
So, I have two problems:
1) blue screen
2) those errors