The issue seems to be fixed by granting authority using (as root) the tool polkit-auth.
Details:
As the user that is unable to mount the DVD, CD-ROM, or some such removable device. Open a bash shell and run:
# polkit-auth
You should see nothing, or at least you should NOT see this
org.freedesktop.hal.storage.mount-removable
IF you do indeed see nothing return by running polkit-auth then the following should fix your problem.
Run the following as root (replace <user_name> with your user account name):
# sudo polkit-auth --grant org.freedesktop.hal.storage.mount-removable --user **<user_name>**
# sudo polkit-auth --grant org.freedesktop.hal.storage.eject --user **<user_name>**
Now as the ordinary user account (the one having trouble mounting), again run the command:
# polkit-auth
Now you SHOULD see:
org.freedesktop.hal.storage.mount-removable
org.freedesktop.hal.storage.eject
Now both mounting and ejecting should work in Dolphin, and possible other apps too.
HTH
Mark