It's not an easy or fun thing to do - but it seems to me the only way it works.
B&O can't even help on this.
I started off by completely resetting the BS2 and using a "clean" card. The important thing is that the software has been upgraded (which I hope yours has) - if not you'll need a PC to do this. Following the instructions on the bo.com website will get you the correct sortware. Don't forget afterwards to put the BS2 into itunes mode. Then connect the lot to your mac and switch to USB (2seconds GO). It should then install the new software for mac. Leopard only works when the software has been upgraded on a PC.
Now the problems start:
Leopard and BS2 do not really like each other.
I then got the Beosound 2 icon in itunes and started to assign playlists. The music I marked in the library then under Advanced converted all the Music to mp3 format - fished it out of the library and dragged and dropped to the playlists. I never knew that itunes and ipods/phones are just as happy with mp3s - the only problem being noe is that you have copies of the originals now as mp3. If you can work out an easier way to handle it - please let me know.
And if you need anymore tips - please let me know. Took me ages to get it set up but I don't regret it - the quality is so much better as my iphone.