Comment 16 for bug 16170

I recently started having the same problem, and realized it was related to a
change I made in my /etc/hdparm.conf file to enable DMA.

I had added the following lines, and found that removing them solves the problem
(after a reboot):

  /dev/cdrom {
       dma = on
  }
  /dev/cdrom1 {
       dma = on
  }

You might want to check if DMA is enabled in hdparm.conf, and try removing it.

-phzi