Just a stab in the dark, but can you try this with the disk plugged in to an external power source (if you're not doing that already?) it looks like the FW bus is being reset, and so the SCSI layer is creating multiple devices when the requests time out.
Just a stab in the dark, but can you try this with the disk plugged in to an external power source (if you're not doing that already?) it looks like the FW bus is being reset, and so the SCSI layer is creating multiple devices when the requests time out.