Number two hit on Google purports a solution. Have you seen it?
http://64.233.187.104/search?q=cache:7ANQ2UIWWeUJ:lists.elvandar.org/pip ermail/spamassassin-users/2004-September/014432.html+%22bayes:+bayes+db+ version+0+is+not+able+to+be+used,+aborting!%22&hl=en
Searching less literally indicates this is an issue across many distributions. Perhaps an email to spamassassin-users would help find a solution.
-- Marc
Summary is: Turn off Spamassassin (kill or service spamassassin stop)
sa-learn --sync -D
sa-learn --showdots --mbox --spam your_spam_box sa-learn --showdots --mbox --ham your_ham_box
Will let you know how this works, I had tried the --sync thing before, but then I would run into the problem a short while later.
-Mike