I think that Yamaha is probably the same drive as I was running before it packed up. I don't think I've ever had a drive too fast problem, maybe you need to increase the amount of time HD Driver waits till checks the drive, it might be taking a bit of time to spin up...
I used to use Spin on the Milan and nothing but grief from it :-(
Still haven't had chance to check the SCSI drive yet, my Mint install is my main prob at the mo.. lol
RE: SCSI CDROM and HD Driver