CD mount problem after DVD rip

[jim branagan]

I used to be able to write and rip audio CD's, with cdda2wav and 
cdrecord, and write data CD's with xcdroast, and to mount data CD's and 
open them to copy out contents.  I am using a Memorex CD-writer/DVD-rom 
drive.

The other day I mounted and read data from a data DVD.

Now I can't rip, write or mount CD's anymore.
I get the message '/dev/hdc already mounted or /media/cdrecorder is busy'.
mount and mtab show /dev/hdc is not mounted.
Shutting down the machine and rebooting does not help.
I can still mount and read DVD's though - KDE says the DVD is mounted, 
and can transfer files from it, but mount/mtab say /dev/hdc is not 
mounted.  Attempting to unmount /dev/hdc results in '/dev/hdc not 
mounted'.  I don't see anything else unexpected mounted.

KDE continues to show CD-ROM as mounted even without a CD or DVD in the 
drive; trying to unmount by context menu fails.  I removed 'autorun' 
from my start folder, and renamed /usr/bin/autorun long ago, so it isn't 
autorun related.

OK, HELP!   What the $#@!* is going on, and how do I get the ability to 
mount CD's back again?

In summary: CD's worked fine until I read data from a DVD, now I can 
only read DVD's????