Postfix/mailman problem

[Eric Smith]

I've got an FC4 x86_64 system with the targeted policy.  I'm only
just beginning to understand SELinux, after reading the O'Reilly book.

I'm trying to use the Postfix MTA with GNU Mailman, using the
postfix-to-mailman-2.1.py script.  I put the script in
/usr/lib/mailman/bin, but it fails.  /var/log/maillog says:

Mar  1 17:26:34 donnybrook pipe[10056]: fatal: pipe_comand: execvp
/usr/lib/mailman/bin/postfix-to-mailman-2.1.py: Permission denied
Mar  1 17:26:35 donnybrook postfix/pipe[10055]: 4D0F150087:
to=<nonpareil-commits at lists.brouhaha.com>, relay=mailman, delay=1,
status=bounced (Command died with status 1:
"/usr/lib/mailman/bin/postfix-to-mailman-2.1.py")

/var/log/audit/audit.log says:

type=AVC msg=audit(1141262794.346:48506): avc:  denied  { execute } for 
pid=10056 comm="pipe" name="postfix-to-mailman-2.1.py" dev=dm-6 ino=786433
scontext=system_u:system_r:postfix_pipe_t
tcontext=system_u:object_r:mailman_queue_exec_t tclass=file

As root, I tried:
% chcon -u system_u -r system_r -t postfix_pipe_t postfix-to-mailman-2.1.py
chcon: failed to change context of postfix-to-mailman-2.1.py to
system_u:system_r:postfix_pipe_t: Permission denied

Why can't I do that, or what should I do instead to make this work?

Thanks!
Eric