fdisk Unable to read /dev/sda

The other day I was trying to partition a drive hooked up via usb. (So it get's /dev/sda as it's device in linux)... I tried a few utilities to access the partition table and all failed, finally, I resorted to fdisk /dev/sda and was told "unable to read /dev/sda" which I thought was peculiar. The drive had come back in a "warranty replacement" swap for another drive and should have been wiped clean and should have been good as well.

I looked online and found people with similar problems, some of which saying they had to use the drive manufacturers tools for partitioning.... I'd rather not if at all possible.... so I took another look at the drive and noticed that the jumper had been set for master. I moved it to cable select, plugged it back into the usb adapter and was able to fdisk away... The moral of the story, is that cable select can make your life easier with usb hard drive adapters (in fact the same can be said of internal ide adapters.)