Colin, This could be a duplicate of the "not enough space" bug (Bug #48355) since only 1GB is available on the USB disk. /var/log/partman says so too.
-- Crash installing onto memory stick https://launchpad.net/bugs/50863 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
