DVD reader access error

Hello,

I have installed a Ubuntu 7.04 OS on my computer, and have a problem
with the DVD drive.
It is seen and installed properly - apparently. When I put a CD in
the drive, the unit is mounted, and I can browse the content. But any
file I try to access is corrupted (I get data access errors).

This drive performs well under windows, and I made the Ubuntu
installation from the LiveCD, so it is not a hardware problem, nor an
error on the CD itself.
When I boot from the LiveCD, I can access any file with no error. But
when I boot from the installed OS on the hard drive, the data
corruption is systematic (even when I try to acces the very same files
from the LiveCD.

I tried modifying entries in the FSTAB file, according to some hints
found here and there on the web (filesystem, charset...) with no
success.

For information : I boot from an SATA hard drive. The DVD drive is
plugged as primary master IDE (I tried secondary master as well).
What may be strange is that the /dev/cdrom entry points to /dev/scd0
(instead of /dev/hda as I would have guessed). I tried to make FSTAB
use /dev/hda but it changes nothing.

Can someone help me ? I really run out of ideas...

When I boot from the LiveCD and look at the "Hardware information"
data, the DVD drive is seen as an IDE device.
When I boot from the hard drive, it is listed as SCSI device.

From what I understand, this is because my drive is a CD burner, and
then must use "SCSI emulation" or something like that. Since the
LiveCD can access the CD, is it possible that this SCSI emulation
makes the CD unreadable ? If so : how can I deactivate it ?