Tag worked. :)

As this was recognized as a DFSG violation, it's unclear to me why the Debian maintainer fixed this for Wheezy but not for Squeeze.

I've put a patched source and i386 binaries to the parkes overlay. It will need to stay open until we've built the amd64/other binaries.

Bogofilter include some documenttation under a license that doesn't permit modification or commercial use.

Specifically, the files say:

This work is licensed under the Creative Commons
Attribution-NonCommercial-NoDerivs German License. To view a copy of
this license, visit http://creativecommons.org/licenses/by-nc-nd/2.0/de/
or send a letter to Creative Commons; 559 Nathan Abbott Way;
Stanford, California 94305; USA.

The files in question are in the /doc directory and are:

bogofilter-SA-2005-01
bogofilter-SA-2005-02 
bogofilter-SA-2010-01

I found these in bogofilter_1.2.2.orig.tar.gz and bogofilter_1.1.7.orig.tar.gz. Other versions may be impacted as well.

The FSF's Guidelines for Free System Distributions say that all the documentation in a free system distribution must be released under an appropriate free license.