CD/DVD drive quit working after dist-upgrade

[David Bruce <dbruce@tampabay.rr.com>]

Hi,

Following a Sid dist-upgrade this AM, my CD/DVD drive no longer works - if I 
try to mount a disk, I get the following.

debian:/home/dbruce# mount -t iso9660 /dev/hdd /mnt/temp
mount: No medium found

Likewise, k3b fails, telling me I need to insert a blank disc.  I used the 
drive before the dist-upgrade for both ripping some audio CDs and burning 
data CDs.  My system is a newly-installed amd64 setup with the kernel from 
the netinst ISO for Etch from about a week ago.

Relevant (I think) lines from /var/log/dmesg:
hdd: Memorex DVD+-RAM 525G v1, ATAPI CD/DVD-ROM drive
...
hdd: ATAPI 48X DVD-ROM DVD-R-RAM CD-R/RW drive, 2048kB Cache, UDMA(66)
Uniform CD-ROM driver Revision: 3.20

Thanks for any suggestions.
-- 
David Bruce