Could be that you need Chipset (VIA, SIS, or whatever you have) Drivers to enable DMA to the CDROM, or maybe you just need to enable DMA - ControlPanel/System/HardDriveIDEControllers/Properties - enable DMA over PIO.
Having moved to XP, I have updated drivers built-in to XP for my VIA chipset on my Abit KT7A-RAID, and have DMA enabled. Also am running Adaptec ASPI 4.71 and all is well.