See my thread on buffer under run on mitsumi 4804TE
Different people say to enable / disable the DMA setting on the CDRW and CDROM drives. What do you think? ON or OFF? Mitsumi say OFF but loads of people say it should be ON both drives

With some older drives, and this may be one of them, enabling DMA can cause probs. The only way to really tell is try it. If it can support DMA it is better, if not at 4x I would not sweat it.
As for your CDROM and HD's unless you have an older PC it's always better to enable it, same thing applies if there are probs, switch it back.


http://www.cdrom-guide.com/ubb/4MoDeRaToRs/SiGnAtUrE_ImAgEs/hoss1.gif