[Mailman-Users] RuntimeError: maximum recursion depth exceeded

[caleb t-r]

Heya,

We are running Mailman 2.1.4 on FreeBSD 4.7, using sendmail 
and mhonarc as an external archiver. 

Every few weeks or so, the qrunner processes stop, leaving mailman locked. 

When I figure out that the lists have stopped running, I run mailmanctl -s 
start. But then a few weeks later, it happens again. 

I check the error log, and the last errors (some shunting, a recursion 
runtime error) happen a few hours before the most recent message to the 
list is sent.

The qfiles/shunt and locks/ directories are full of old stuff. Should I be 
cleaning these out somehow?

Any other hints? 

Thanks

Caleb T-R