IDE transfer modes

If I set my IDE drives up like this:

Primary master = 9gbHDD ATA-100
Primary slave = CD-Rom UltraDMA/33
Secondary master = 40gbHDD ATA-133
Secondary slave = CD-RW UltraDMA/33

what effect will the CD devices have on the transfer rate?

It seems like in this setup, the HDD transfer rate for each channel would only be UltraDMA/33, not ATA-100. Doesn’t each IDE channel revert to the lowest common transfer speed?

Is this correct?