Just a note that I couldn't get a M-Audio Firewire Audiophile working on my Titanium PowerBook. The installer did its job but (a) no noise comes out of the Audiophile unit when selected under Sound Manager (b) Logic and Ableton Live fail to work with the Audiophile ASIO driver selected.
The Powerbook and cable test good with a MOTU 828 Mk1, and the Audiophile unit tests good on a different computer with MacOS 10.5.8 installed.
My guess is that the Audophile unit I have has a more recent firmware that's incompatible with the MacOS 9 drivers. I can't find any firmware installers to downgrade the unit.
One last note - the MOTU 828 Mk2 does not support MIDI under MacOS 9 - refer to the manual and the SOS article linked to in the list above.