POST comes way before any operating system even gets off the ground.
The message is what it is. You do not have an 80-wire (NOT pin) IDE cable on the secondary channel. Neither do you normally requore one for optiacl drives.
Look at the two IDE cables in your system and you will soon see the difference in the number of wires in them (unless you have round or sheathed cables).
Anyway, you can ignore the message unless you really want to get a second 80-wire cable. It will have no practical effect. I have come across some optical drives that were not happy with 80-wire cables - but more recent ones should be OK, if you want to replace the cable.