Hola! en la página de digidesign pone lo sigüiente:
Pro Tools LE 6.7 is officially supported on Mac OS X 10.3.2, 10.3.4, 10.3.5, 10.3.7, and 10.3.8 (Panther) with the following systems on Power Mac G5, Power Mac G4, iMac G4, PowerBook G4, and iBook models*:
Digi 002
Digi 002 Rack
Mbox
... quizás si debas actualizar el osx. El enlace digi es este:
http://archive.digidesign.com/compato/osx/os.cfm