I've installed SpamAssassin (3.2.4), including DB_File to use the Bayesian
filters.. If I execute spamassassin directly from the command line, it
executes as expected and uses the bayes filters:

% spamassasin -D bayes < spammsg2.txt
[6868] dbg: bayes: tie-ing to DB file R/O
/home/jeff/.spamassassin/bayes_toks
[6868] dbg: bayes: tie-ing to DB file R/O
/home/jeff/.spamassassin/bayes_seen
[6868] dbg: bayes: found bayes db version 3