Thanks jlliagre.
No... what I did was (Solaris 10 was preinstalled on the workstation):
- installing the last "tools and drivers cd" of the workstation
- installing Java System Application Server 9
- installing Netbeans 5.5.1
and everything was fine.
Yesterday I upgraded the system and since at first reboot audio wasn't working any longer.

If I manage doing a backup (that's why I upgraded instead of performing a fres install) I'll repeat the procedure and if it's the case I'll file a bug.
By the way, is there something I can do to troubleshoot why the driver doesn't want to attach?
Bye,
Enrico.