I have the SOHC-5232K. It works perfectly with either cable. With a 40-pin cable, it is recognized as "Ultra DMA 2" (33MBps). With an 80-pin cable, it is recognized as "Ultra DMA 3" (44MBps). I have used a couple of these drives in a few different motherboards and have noticed, some BIOSes refer to the drive as "Ultra DMA 0", however Windows will always see it as "Ultra DMA 3" when a 80-pin cable is used.
BTW, I love this drive. IMO, it's the best Combo drive available. Triple Colored LED, Ultra DMA 3, ability to patch to RPC-1 without modified firmware.
-LaTeR