SCSI CD, reported by kernel, isn't there.

[Alan Eugene Davis <adavis@netpci.com>]

Recently, I shuffled some hardware on my working new Potato system;
mainly, I installed an SB Live sound card (compiled Creative's source
with both 2.3.35 and 2.2.13, and both worked, _nominally_).  

Now I am having some trouble with the SCSI CD.  The kernel reports the
SCSI adapter and the CD during boot up messages.  But when I try 
   mount -tios9660 /dev/scd0 /cdrom
or to use a cd player, nothing---this is not known to the kernel as
a block device

>synapse:/home/adavis#  mount -tiso9660 /dev/scd0 /cdrom
>mount: the kernel does not recognize /dev/scd0 as a block device
>	(maybe `insmod driver'?)
>synapse:/home/adavis# 

This is not a module.  SCSI support is compiled into the kernel
itself.  

Where can I find out the device associated with the recognized drive?  

What else can explain that the kernel reports the device, but it is
not available to be used?

Thank you for any, even the slightest, clue.  I hope this is not
off-topic.  

Alan  
-- 
adavis@netpci.com

"An inviscid theory of flow renders the screw useless, but the need
for one non-existent."    ---Lord Raleigh (John William Strutt),
                          or else his son, who was also a scientist.