Excellent trouble shooting skills, and thank you for posting such a thorough description. I mark this as technician of the day!
Well, the next step is to see what is in common with the two results?
One works, one does not. What do you think is the problem?
As long as the connections are made securely, and you are 100% certain both are administered correctly, what do you think is wrong with the disk that wil not load?
I am 99% certain it is the disk is bad. You can always boot up into DOS and try to run FDISK. Have you tried that?