Hi all
I have sort of resolved it.
My default distro configuration, from Slackware 9 compiles ATAPI CD-ROM
support, the main SCSI support, and the ISO9660 filesystem into the kernel.
I usually make these as modules, to make the kernel a little smaller and
thus use less memory. If I leave these options compiled into the kernel,
there is no problem. However, if they are all as modules, it doesn't work.
DMA is enabled by default, and my DVD-ROM drive is set up to be mounted
from /dev/cdrom which is symlinked to /dev/scd0 when using SCSI emulation,
and /dev/hdc when using straight IDE. I usually have SCSI emulation set up
for burning.
This has never been a problem for me in previous kernel versions. I will
live with it now, as I guess it is a small kernel size increase and should
not change the performance in any great deal.
Thanks again
Luke