DVD drive problem - DMA

Okay, first off, I did try everything I have knowledge of before I resorted to ask for help.

I recently built a new computer, everything works fine except for one thing, I can't enable Ultra DMA 4 on my DVD drive. (PIO transfer mode works fine.) When I enable it by having Windows uninstall and install my secondary IDE controller, explorer crashes and reverts to PIO. I checked the jumper setting on the DVD drive, it was set to master (It's the only DVD drive in this PC, and on the second IDE controller.)

There's nothing I can do, and burning/reading DVDs is really slow and makes everything lock up if I'm doing anything else ;_; Please help, and thanks for any replies.

My epeen (specs):
ASUS K8N-DL nForce 4 motherboard
Dual AMD Opteron 242
1GB ECC RAM
DVD drive - LITEON SHW-160P6S
GeForce 7300LE (If it matters...)

If you have only one drive on the cable, but a cable with 3 connectors, did you used the far end?

Here is a quote from pcguide.com, it's a great page btw:
"it is not a good idea to connect a single drive to the middle connector on a ribbon cable, because the "stub" of left-over, unconnected cable causes signaling problems. With Ultra DMA this "stub" connection is not just "not recommended", it is illegal: a single device must be at the end of the cable. The other reason is that since these cables support cable select inherently, the position of each drive on the cable matters if cable select is being used. With these two needs combined, it just made sense to design the cable so that drive positioning was explicitly clear."

sauce: http://www.pcguide.com/ref/hdd/if/ide/conf_Cable80.htm