ok, this is admitedly not the most knowledgable of posts, because i'm not sure quite how your set up is run...
but i'm pretty sure you've got to throw the music on to the ipod through itunes for it to be able to see it... either that or you need an alias or something (*this is the part i don't know about*) because when you put the music on your ipod in disc mode it (obviously from your results) isn't noted by the music player part of the ipod... this is part of apple's security thing... (don't steal music). so, the easiest way is to just plug the ipod into your imac, but you can't do that, right? (no firewire)...
other ways...
thinking.
poocat.