No other devices are attached to the machine beside the Adrenaline via FireWire!
I have the keyboard and the dongle attached via USB.
On my MBP I have MC 4.0.5 installed (3.1.2 on the G5). When I attached the Adrenaline It didn’t ask for a firmware update, but worked fine!
Matthew! When you asked me about the OS on the CPU I come to think of another thing; I have had another OS (Tiger) installed on the same CPU at the same time with Leopard but on another disk-partition. I have now erased the partition. Could that disturb something between MC and the Adrenaline..?