A UDMA cable has 80 wires instead of 40. Here's a pic (80 on top, 40 below):
If you use CS, both drives must be set to this. The top drive will be the master, the middle one the slave. If it is a UDMA cable, you will likely have to use CS as the jumper setting. Try hooking both HDDs to the same cable and setting both jumpers to CS.
If this doesn't work, try keeping the drives on the same place on the cable and set the top one to master and the middle one to slave.
One of the two IDE slots on your motherboard is for your HDDs (the first one generally) and the other is for any media drives - CD/DVD ROMs.
Floppy drives have their own little slot.

Bad pun, I know...
Anyway, try moving the jumpers. I am almost certain this is your problem.