I have a weird problem. Have just cleanly reinstalled Feisty and added
some applications via Synaptic etc. I now find that my DVD drive will
only read some CD/DVD but not all.

When I find that a disc has not been mounted, I go to Places-Computer.
I see two icons
CD-ROM 1
and
CD-RW/DVD+/-RW Drive
(this is odd in itself as I only have one drive)

When I click on cd rom 1 I get:
Unable to mount the selected volume.
mount: special device /dev/scd0 does not exist

When I click on the other icon I get
Unable to mount media.
There is probably no media in the drive

It is not a fault with the drive or the discs as they work ok when I
boot the PC into Windows.

Some discs will load OK but I have not spotted a pattern of failure.

Can anyone help please ? My faith in Ubuntu has been shaken and I want
to see the light again !