secondary slave, you mean the cdrom is on the second IDE channel with its own cable, if it is then it must be set to MASTER if it is the only device.
if you mean the hdd and cdrom are both on the same PRIMARY IDE cable then you could try setting the cd-rom to cable select ( jumper setting on the back). if this does not work try the cd-rom as MASTER on the 2nd IDE channel as above.
Fireball If in doubt get the Ball Pein Hammer out