WD 120 gb hard drive in 1394 external enclosre can't be detected

[Barry Yu]

Fc3 failed to detect my Western Digit 120 gb hard drive in a 1394 
firewire enclosure ( but it works in usb2 mode), the whole combination 
is : 1394 + usb2 combo pci add-on card, the external enclosere with usb2 
and 1394 ports. FC3 can detect the pci card, and can detect hard drive 
when used in usb2 mode.
Any advice will be appreciated.