Sorry to trouble you, but I've been having a problem simliar to voxxchubbs regarding switching audio tracks on a dual audio ogm. # doesn't work, it just says Audio: (1) Unknown at the top and nothing happens.
You said to pm you for specific instructions about the command line or terminal, right? I need a detailed explanation for that since I couldn't get it to work myself by just going into preferences.
I have an intel based macbook pro, and I'm using the most recent version of mplayer, the anime layer one, I think.