I can confirm the original problem. Unlike dkhelmet's
problem on OpenBSD with incorrect permissions, my check_perm
reports No Problem. The work-around of commenting out the
function twiddle() and the os.path.walk on lines 342ff works.
Enviroment is NetBSD 1.6.1, with python 2.1.3 and mailman
2.1.4, both installed from NetBSD's pkgsrc system (ie.
mailman gets installed with DIRSETGID)