Problems with Orange micro Adapter, looking for Ratoc FR1SX SCSI-Firewire-Adapter

I used an Agfa DuoScan T2500 an an Umax 270plus (both 25pin SCSI) via
VueScan on a Windows system and recently switched to an Apple Intel-
iMac, so i have no SCSI connection anymore.
I have bought an Orange micro SCSI-Firewire-Adapter, which worked well
with VueScan an the Umax.
Unfortunately, VueScan fells asleep when I try to start a preview with
the Agfa scanner. (At least the system sees the scanner)
I'm not using the additional power supply of the adapter, because I do
not have it. Maybe that is the reason for freezing. Does anyone knows
the specs of the adapter? I would buy an new one and give it a try,
but I am afraid I could barbecue my adapter/scanner.

Has anyone heard of that problem before?

My second question is: Does anyone wants to sell a Ratoc FR1SX SCSI-
Firewire-Adapter?
It is tested with the combination that I am using, so it would work
for sure.

Chris

PS: Please excuse my english.