I have a similar problem with my new Plextor DVD R-RW PX-740A.

I discovered this while trying to install Ubuntu 5.04, and then after its failure did a comparison with my KNOPPIX 3.8.1 live cd which had worked previously before adding the newer drive. All were MD5'd successfully and on name brand media.

After a lot of scrolling I got this...

end_request: I/O error, dev hdc, sector 745056
Buffer I/O error on dev hdc, logical block 186264
hdc:drive not ready for command
cloop: read error at pos 37817527 in file /cdrom/KNOPPIX/KNOPPIX, 34592 bytes lost
cloop: read error -3 uncompressing block 16086
65536/0/34592/0 378317527-378352119
Buffer I/O error in device cloop0, logical block 514778
Bus error /linuxrc: cannot create /var/run/utmp:dir nonexistent
kernel panic - not syncing: VFS:unable to mount root fs on unknown block (1,3)

So I'm dead in the water until I put another CD drive in my Dell Optiplex. Maybe I'll see if there is a firmware update.

[edit: a bit later...] So here's something interesting I happened to dig up. My Plextor has the same chipset as the BenQ 1640 listed in this thread! Go look here. http://www.anandtech.com/storage/sho...spx?i=2482&p=2 A firmware upgrade for me didn't help. I think we're both hosed... bummer...