I haven’t read all this thread, since it went ballistic Sunday, too much to read but there seems to be a misconception this is an sa-update problem from what I have read. This is not the case the if perl_version causes problems in sa-learn and spamassassin too.
What dose seem strange is that spamassassin --lint picks up the version correctly "Perl 5.012004" so perl_version is doing something wrong if the version can be picked up numerically elsewhere, surely in the next release of spamassassin this can be changed and it can play nicely with older versions of perl.