Today's drives and machines use that new 80 conductor CABLE SELECT method. You set all the drives to CS or Cable Select then the master is on the master connector and the slave is on the slave connection but both drives are set to Cable Select.
You didn't share exactly what jumper settings, connections and cable type you are using.
Running dell Opti-plex 240, pent 4, and XP. Have been running two 40 gig hd's, mirroring primary drive onto secondary drive. Primary drive quit, so I installed new 80 gig drive. Just pulled old drive, plugged in new drive, set jumper. Nothing would work, so I pulled BIOS battery, then new drive was detected, but not slave drive, (I did not touch slave drive in swap). Made sure all cables, and power supply was connected properly, still nothing. Changed slave drive to another computer, and it would boot, so I know it is good, it will even boot on this machine if set to primary. But, I can not get pc to recognize it when set as slave, (other machine will see it when set as slave). So far the only thing anyone can tell me is to make sure cables are snug, which they have to be if it will boot when set as primary. I have some important data on it which I want to just move over to new drive, and I want to be able to use it to backup important data. Thanks in advance for any help you can give.