Comment 6 for bug 266009

I also experienced a similar problem, but was able to fix it.

In my case, it appears to have been related to a python
version number: the qrunner program was running against one
python version, but was actually using features defined in a
later version.

In my case, I had Python 2.2 installed with the operating
system, but had subsequently installed version 2.4.1.

I fixed the problem by re-installing mailman with an
explicit reference to the later python version (./configure
--with-python=...), and then rebooting the system. After
that, it was fine.

(The reboot was to get qrunner running against the later
python version: it seemed the old version was running
whatever I might do with chkconfig or /etc/init.d/mailman.
Rebooting was maybe a sledgehammer to crack a nut.)