I thought that Stretch meant that he had this configuration:
Primary Master: Mitsumi CD-RW
Primary Slave: Pioneer DVD
Secondary Master: Lite-On CD-RW
Secondary Slave: None
I could be mistaken though.
Edit: If this is what Stretch is using, that should be fine, too.
Anyhow, you are right when you say that I have never tried CS on 40-wire cables. However, it appears to be common knowledge that CS doesn't always work with 40-conductor cables. I have also heard that 40-conductor cables that are compatible with CS sometimes have the middle
connector as the master and the end
connector as the slave, which is exactly opposite to the way it's done with an 80-wire cable.