Plexwriter 48/24/48A - UDMA Issues

I’ve been using my Plexwriter 48/24/48A for about a year
and it has been running really well.

But then I remembered that I haven’t been using it at its full potential.
I’ve had it under DMA-Mode 2 while it’s capable of UDMA-Mode 2.
Burst speeds of write/read could be doubled at Ultra DMA.

But ever since I’ve switched it to UDMA
ALL of my recorded media has been unusable/corrupted.
None of them could be read by any type of CD-ROM drive.

I’ve already verified that I have a 40-pin ATA cable hooked to it
(Although I’m not certain about its more detailed specifications).

I used Nero 6 Ultra Edition to burn my media
and I am pretty certain that any other program would not change its current recording status.

Please, I’m asking for advice to resolve this issue.
Much will be appreciated.