"IN BOOLEAN MODE" should definitely not be in there. Those are keywords. The replaceable parameters can *only* replace literals (and then, only some litarals). If anything works, it's 

my $table_lit = $dbh->quote_identifier( $table );

my $stmt = qq{
   SELECT *
     FROM $table_lit
    WHERE ( MATCH( Author ) AGAINST( ? IN BOOLEAN MODE ) )
    ORDER BY Title
};

...

$sth->execute('+herman +melville');

[download]

If the above doesn't work, the following will definitely work: 

my $table_lit   = $dbh->quote_identifier( $table );
my $pattern_lit = $dbh->quote( '+herman +melville' );

my $stmt = qq{
   SELECT *
     FROM $table_lit
    WHERE ( MATCH( Author ) AGAINST( $pattern_lit IN BOOLEAN MODE ) )
    ORDER BY Title
};

...

$sth->execute();

[download]

Update: Added backup method.

In reply to Re: DBI/DBD::mysql placeholders and full text searches by ikegami
in thread DBI:MYSQL placeholders and full text searches by Gnat53

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