Among other possible fixes, try replacing the drive cable (use
good quality 80 conductor UDMA cable, not 40 conductor).

"Nil" wrote in message ...
One hard disc attached to the motherboard's SATA port, and one DVD/CD
burner attached to the regular IDE port. Every so often, I check and
discover that the DVD drive's controller has "fallen back" from DMA
mode to PIO. I get it back to DMA mode by deleting that errant Primary
IDE Channel from Device Manager and letting Windows redetect it.
Eventually, though (days, weeks, I haven't figured the pattern out
yet), it lapses back to PIO.

Can anyone suggest what might be causing it and perhaps a cure?

- Samsung 18X DVD+-R DVD Burner IDE Model SH-S182M/BEBN
- Western Digital Caviar SE16 WD2500KS 250GB 7200 RPM SATA
- ASUS P5L-VM 1394 motherboard
- Windows XP Pro, SP2