Firewire Audio Interface Not Recording Digital Audio, recording digital audio through Firewire [hub] Options

[iDavid]

I have been trying to record the Line Out from an Akai EWI4000 breath controller. The signal is weaker than the headphone Out mini-1'8" . Even with the patches volume at highest level -30- there is barely anything. I am using a Behringer FCA202, they claim the driver for Mac is Core Audio and I can adjust the bit depth and sample rate in the Audio/MIDI set up. The Behringer has a a/d converter and I wonder if the Firewire protocols on my ancient Mini PPC are even seeing the incoming digital audio. I use a USB mic and it works fine.
I saw something on the Apple site about possible incompatibility of the old Firewire protocol and a new set called SDK24-anyone else recording digital audio through a Firewire powered hub? The La cie FW HD boots and performs quite well, although i did get an error"-2" a few times. the Midi connection works as I do get a track of Midi data. I have tried it in an aggregate device and by choosing the behringer's digital audio output manually but nada. A better audio/Midi interface would be better but if the PPC G4 1.5ghz can't handle Firewire i might as well forget about FW and try to find a USB interface.
Please, any suggestions will be greatly appreciated.