DMA dilema, will not get into DMA even i delete it

I have search on slow burning problem, and I did check it out and it said that it should be on UMD mode 2. However mine can’t be change i check in teh BIOS and delete it like this threath said but it won’t go into UMD mode 2 for me:

Here is the computer spec:

Running 2 plextor 712A
-in the device driver I have 2 Primary IDE channel and 2 Secondary IDE channel
-the 2 plexotr is connected in IDE1, while 2 HD is connected into IDE0
The master plextor 712A is burning fine, however, the slave one will not burn more then 2X.

1st Primary IDE channel refer to A easy reference
2nd Primary IDE channel refer to B
1st Secondary IDE channel refer to C
2nd Secondary IDE channel refer to D

All of the IDE is set to DMA if available, however only the ‘B’ is on UDMA mode 5, guess this is the HD. And ‘D’ is in UDMA mode 2, while other is Not Applicaple under current xfer mode.

Any help or recommendation guys? As before my plextor works fine. I have try switching media also but no lucks, its the DMA problem but i can’t force it to be in DMa on both only 1 now. Also i have check the biios its auto .

is this a self built system or a commercial one? what kind of cable are you using on the Optical drives and have you tried another cable?

i haven’t try different cable, but i will right after this post. As far as the system it is self build. i measn the copy works before how come it slow down?
Intel 2.6 GHZ
1G ram
DFI 865Pe motherboard