No cdrom device

[Ed Jabbour <ejbr@att.net>]

CDROM tray will not respond to "eject":
========================
[Fri Dec 23] edj:~$ eject
eject: tried to use `/media/cdrom0' as device name but it is no block device
eject: tried to use `/dev/scd0' as device name but it is no block device
eject: unable to find or open device for: `cdrom'
=========================

Perhaps related, dmesg reveals:
==============================
6.720030] ata1: link is slow to respond, please be patient (ready=0)
[   11.704028] ata1: device not ready (errno=-16), forcing hardreset
[   16.900028] ata1: link is slow to respond, please be patient (ready=0)
[   21.716029] ata1: SRST failed (errno=-16)
[   26.912027] ata1: link is slow to respond, please be patient (ready=0)
[   31.728027] ata1: SRST failed (errno=-16)
[   36.924030] ata1: link is slow to respond, please be patient (ready=0)
[   66.772029] ata1: SRST failed (errno=-16)
[   71.800028] ata1: SRST failed (errno=-16)
[   71.811047] ata1: reset failed, giving up
[   71.811185] ata2: port disabled--ignoring
=============================

modprobe cdrom sr_mod:
==============================
FATAL: Error inserting cdrom (/lib/modules/3.1.0-1-686-
pae/kernel/drivers/cdrom/cdrom.ko): Unknown symbol in module, or unknown 
parameter (see dmesg)

728.919036] cdrom: Unknown parameter `sr_mod'
===================================

Nor will the tray open manually, except that it does if on reboot, I push the 
button before GRUB takes over.   Running testing with the 3.1.0-1-686-pae  
kernel, although the problem persists no matter which kernel I boot into.

Any advice, pointers, etc. appreciated.