I have a pioneer DVD-106S. I am using Cyberlink powerDVD, WinDVD, and windows media. For each one, it would have the same choppy playback, from the beginning. I'm using winxp pro, which has enabled DMA automatically at Ultra DMA 4. I have it as the only drive. I've tried changing it to PIO and back to DMA but to no avail. What else can I do?