Tried with today's image, /etc/apt/sources.list is valid, the dvd list file is called /etc/apt/sources.list.d/dvd.list so is also valid, /var/lib/apt/lists contains the required package lists. apt-cache, apt-get and software-center work out of the box in the live environment.
Tried with today's image, /etc/apt/ sources. list is valid, the dvd list file is called /etc/apt/ sources. list.d/ dvd.list so is also valid, /var/lib/apt/lists contains the required package lists. apt-cache, apt-get and software-center work out of the box in the live environment.
Marking the bug Invalid.