Did you add any peripherals to your system that may have put a stress on your PSU. A Bad or fualty power supply is like Multiple Sclreosis in the human brain.....An infinite number of systoms that point to other things that may just be the PSU. I always sub out the power supply in a computer I am repairing just to make sure I'm not going to be wasting alot of time. If it is not the PSU then I doubt it is a DMA issue unless you recently changed your DMA settings for that DVDrom. If it is XP we are talking about, then you would have had to change that protocol yourself. Did you? If it is not the power supply or DMA settings....time to buy a new DVDrom.
Noli Nothis Permittere Te Terere!!
EVGA 680i, Dual EVGA 8800GT'S (650/950), 4 gigs OCZ DDR2 1066, Intel Q9450 at 3.8 Ghz, Koolance Water Cooled, Dual Plextor16x DL DVD+/-RW. Dual WD 250gb 16mb Cache Sata 3.0. 3DMark06 score = 19,168.