I currently have a Plextor PX-708A and a PX-W4012A. I had both of these drives connected to the secondary IDE channel of my NForce2 board (using the Microsoft IDE driver) and they were both working happily in Ultra DMA mode.
I have since acquired a Silicon Imaged Si0680 based EIDE card and attached each of the writers to this card, one per channel, each as a master. The card is interfacing with them on Multi-word DMA Mode 2.
Why won't it work on UDMA2? Both the drives and the card support it!
I am using the appropriate 80 pin 18-inch IDE cables for the interfacing, and the drives are the only things on their IDE channels on the EIDE card.