Even if you use a usb-stick the live sesion would create a virtual /cdrom. Did you use Ubuntu 11.04 or 10.10? Maybe it would help if you would attach to the bug report the /var/log/syslog file.
Please ignore my previous comment. I think my bug might be different though.
In my syslog of the live session, after doing the installation, there was something like this:
Mar 25 15:26:02 ubuntu apt-setup: W: Skipping nonexistent file /cdrom/dists/natty/main/binary-i386/Packages
Mar 25 15:26:02 ubuntu apt-setup: W: Skipping nonexistent file /cdrom/dists/natty/restricted/binary-i386/Packages
....(other related errors)....
Rob,
Even if you use a usb-stick the live sesion would create a virtual /cdrom. Did you use Ubuntu 11.04 or 10.10? Maybe it would help if you would attach to the bug report the /var/log/syslog file.
Please ignore my previous comment. I think my bug might be different though.
In my syslog of the live session, after doing the installation, there was something like this:
Mar 25 15:26:02 ubuntu apt-setup: W: Skipping nonexistent file /cdrom/ dists/natty/ main/binary- i386/Packages dists/natty/ restricted/ binary- i386/Packages
Mar 25 15:26:02 ubuntu apt-setup: W: Skipping nonexistent file /cdrom/
....(other related errors)....