Just for posterity's sake, I did manage to resolve my problem. The culprit was the DB_File Perl module. On my Red Hat box it was compiled against the db3 library, while on my FreeBSD box it wasn't. I downloaded the DB_File source, tweaked its config.in file to compile against my db4.1 library and rebuilt it. Presto, SpamAssassin could read my old Bayes files. I'm taking this over to the FreeBSD lists to see if we can get this sort of thing to happen automatically.
W
