loads of expire files filling up /var/spool/spamassassin/nobody

[Calum Mackay]

Is it just me that gets loads of files bayes_toks.expire* filling up 
/var/spool/spamassassin/nobody ?

I seem to get a 10MB file of this form in there for every single email - 
for every user - SA handles :(

I've obviously messed something up badly in my config, but have no idea 
what...

I'm running Debian's 2.64-1 with AWL via procmail:
        :0fw: spamassassin.lock
        * < 262144
        | /usr/bin/spamassassin -a
I'm not using spamd.
I have nothing other than "whitelist_from" entries in my 
~/.spamassassin/user_prefs .

I have these in /etc/spamassassin/local.cf :
        # use this for a system-wide whitelist:
        auto_whitelist_path      /var/spool/spamassassin/nobody/auto-whitelist
        auto_whitelist_file_mode   0777
        # Bayesian learning
        bayes_path /var/spool/spamassassin/nobody/bayes
        bayes_file_mode 0777
I've checked the FAQ to no avail. I can't search the archives since the 
GMANE server seems unresponsive.

any ideas? Is it just that I should be running some expire process from 
cron to clear these up?

thanks very much.
cheers,
calum