apt-file "read_config_file" without a package or object reference

[google@richarddesmond.com]

Hi,

When running apt-file on my sid box (for example with no args) I get
the following error:

$ apt-file
Can't call method "read_config_file" without a package or object
reference at /usr/bin/apt-file line 319.
BEGIN failed--compilation aborted at /usr/bin/apt-file line 367.
$

apt-get works and I've apt-get'd apt-file and all it's dependent
packages to the latest versions. I've searched for ages but no luck -
as a last resort can anyone suggest what to look into?

TIA...

Alex.