Yesterday a silly oversight in the packaging of
udev in Ubuntu/Lucid produced a breakage that consistently makes
dpkg barf. Here's a simple command line recipe to recover from it. In your terminal application, type:
sudo sed -i 's#copy_exec /lib/udev/firmware.sh#copy_exec /lib/udev/firmware#' /usr/share/initramfs-tools/hooks/udev && sudo dpkg -a --configure && sudo aptitude update && sudo aptitude safe-upgrade
...then press enter. You should be able to resume normal operation right after.
PS: as suggested by others, I revised the above snippet to use
sed locally, since not everyone has