Yeah, I got it:

You need JBindery to start Java Application on Mac. With it everything works 
(but the gui is pretty slow on the mac here). You find JBindery in Apples MRJ 
SDK you can recieve from their pages.

Another issue is that when you save adsyn files or orchesters, MAC relates it 
to JBindry and let you open the document only with it. Any hints to break 
this tide?

Soon I post MAC screenshots to 

http://members.aol.com/additiv

where you can find hYdraJ, the Javaversion of hYdra, the free adsyn file 
editor.

Greetings,