I could not replicate your problem.
I am using Perl 5.6.1, DBI 1.30 and DBD::mysql 2.1018

#!/usr/bin/perl -w
use strict;
use DBI;

my $dbh = DBI->connect("DBI:mysql:test;host=localhost;"
    ."mysql_read_default_file=$ENV{HOME}/.my.cnf",
    undef,undef,{RaiseError => 1});

$dbh->do(qq{drop table if exists testq});
$dbh->do(qq{create table testq (i int not null, c varchar(50))});
my $sth= $dbh->prepare(qq{insert into testq values (?, ?)});
my $i = 10;
my $msg = 'tengo todo por aprender ¿quien quiere enseñarme?';
$sth->execute($i, $msg);

my @results = @{ $dbh->selectall_arrayref(qq{select * from testq})};
print "@$_\n" for @results;

$dbh->disconnect();
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This code accepts the variable, inserts it into the table and retrieves the values correctly.
Can you make a simple test case, with appropriate values, so that we can evaluate what is wrong?
Use the above code as a template.


update 12-Feb-2003 17:50 CET
Tested the above code with DBD::mysqlPP and it works as well.
Just replace the connection string with the following.

my $dbh = DBI->connect("DBI:mysqlPP:test;host=localhost;",
    "gmax","mysecretpwd",{RaiseError => 1});
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Therefore, the placeholder mechanism is not the culprit.

update 2
The mistake is in the DBD::mysqlPP driver. Check the Changelog. Versions prior to 0.04 are affected by a quoting bug, which was corrected 20 days ago!
So, after all, the culprit was the placeholder mechanism. Just update your copy of DBD::mysqlPP

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