I have taken the second firewire port, updates to 10.4.8 and installed the brand new MUA-Drivers from Motu. Now, it works.
Thanks to Motu, great work.
---> Load the new "Driver Version" from the Download Center and then, it will work. If not, try to change the FW port or change the cable. I've used the same, and even the port should work, so I thinkm this is based on the drivers

Good luck everyone