Was this problem happened in SpamAssassin 3.0 or early version?
I saw the same issue with SpamAssassin 3.0, it complained:
Argument "n.nn" isn't numeric in addition (+) at /usr/local/lib/perl5/site_perl/5.8.4/Mail/SpamAssassin/Conf.pm line 238.
However, I have the "bayes_auto_learn" line set to 1.
Hou, sorry I mist your post when it was fresh.
In general the "Argument "n.nn" isn't numeric in.." type complaints in Conf.pm usually mean you've got a configuration line in your config files which requires a numeric parameter, but you've left the parameter off, or put in something text based like "yes" instead of 0 or 1.
In this case, you've got a score statement in your config that's lacking a numeric score, or you've got a space in the rule name.
(For reference, i figured out what kind of item it was by looking at line 238 of Conf.pm of SA 3.0. That line is part of the score parsing)
Check your score statements for typos. They should be of the format:
score RULE_NAME 0.0 -or- score RULE_NAME 0.0 0.0 0.0 0.0
You MUST have 1 or 4 score values, you cannot have any other count of score values. (0, 2 or 3 score values will also produce this error)
