I have my Pioneer DVD-Rom hooked up as secondary master and my TDK 48x CD-RW drive hooked up as secondary slave. This configuration works well for me, but doing direct CD copies on the fly does slow down the write speed of the CD-R and tops off at around 30x.
If you planning on doing a lot of direct CD copies on the fly, then I would suggest you placing the DVD and CD-RW drive on separate IDE cables. This will help increase the data transfer and write speed when doing direct CD copies on the fly. If your not doing a lot of this, then the DVD and CD burner on the same IDE cable is okay. Also, it doesn't matter if the DVD or CD-RW drive is the master or slave on the secondary IDE channel, just try it one way and if that doesn't work, then try setting the jumpers in the opposite way.