Check your ATA cable and make sure the drives are connected properly on it. If you are using the new 80 wire/40 pin cable, make sure you are connected as follows..
Blue: The blue connector attaches to the host (motherboard or controller).
Gray: The gray connector is in the middle of the cable, and goes to any slave (device 1) drive if present on the channel.
Black: The black connector is at the opposite end from the host connector and goes to the master drive (device 0), or a single drive if only one is used.
Murray