on CS also called cable select. the farthest end drive will be treated as MASTER and middle drive will be treated as SLAVE.
although this should work fine as well, as enter into BIOS, and there might be option of Detect Drives. and it will automatically detect the drives.
also see, if you have properly inserted the DATA/POWER cables into hard drive.
if this doesnt work, there might be possibilities:
1: have you properly FORMAT your hard drive? (this means full format, rather than quick format, assuming that h/d is new)
2: thre coems 2 types of data cables, 1 called 80-conductore cable (has very thin lines) otehr called 40-conductor cable (has think lines), as 80-conductor can handle higher rate of datra trasnfers (100/133) therefore its recommended for hard-drives, and 40-conductor for optical drives as they have maximum data throughput of 33/66.
so change your cable as well to 80-conductor.
and lastly, rather using CS, force the detection, make jumper for H/D as Master and Jupers for DVD as slave. this will treat H/D as master and DVD as slave regardless where you have attached them.
problem still persists, consult the doctor