problems with external FW enclosure


I have an external 4 bay firewire enclosure. The enclosure has two IDE controller cards. I have upgraded one of the cards to a FWB-IDE10D, which is a new 1394b Oxford chipset with 2 Firewire 800 ports. My problem occurs when I connect two drives to the card. If both drives are connected, neither of them will show up on my Mac and the error light (on the enclosure) lights up on the bottom drive (first drive on the IDE cable). If I install only the second drive (second on the IDE cable), I have no problems. I have removed the bay drive docks and switched them around, with no success. I have installed a new IDE ribbon cable, with no success. If I install only the first drive, it does not work. I have played with all the jumper combinations, including Cable Select, without luck. In some of my many different combinations, I can get both drives to work (almost). When both drives mount, I can read/write to disk 2, but can only read from disk 1. When I try to write to the drive (or unmount or any other function that requires a drive write) It tells me there was an error (-50) and will not complete. I am out of ideas. Can it be the FWB-IDE10D card? The card can be set up for RAID, but I don't think I have it set that way, though I can't find any good documentation to confirm that. Any help is appreciated.