Yeah, we might have missed something obvious here... but I am not positive about how this would be interpreted. What I mean is, if you didn't have the proper device mounted, I'm guessing HDToolBox would not have brought the drive up to be installed. But, out of curiosity, what model computer are you trying this on and what's your ribbon cable hooked to? Hooked directly to the computer or do you have a card such as a GVP or A2091 Hardcard?
And you're sure it's terminated properly? Set to last device?