DPKG locale problems on Debian Lenny

For the techs. If you find that dpkg is churning out the following (or similar) on Debian Lenny:

perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = (unset),
LC_ALL = (unset),
LANG = "en_US.UTF-8"
    are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").

You can fix by:

aptitude install locales
dpkg-reconfigure locales

and make sure that at least one locale is selected and generated.