hhhm, MPlayer has libdvdread,libdvdcss,libdvdplay already installed within the source, did you do it for Xine? try diffrent video modes:
$ mplayer -vo x11 dvd://1;
You gotta have X11 running, not under root. you also have to have correct permissions to /dev/sr0 if you're using scsi-ide emulation.