Apache::DBI and DBD::mysql ping not working

Hi,

I've been digging around in my mod_perl-based apps and trying to figure 
out why setting up the DB connections for pinging is still randomly 
producing first-thing-in-the-morning "mysql server has gone away" 
errors.  I read up about the morning bug and such (adding ping() to 
mysql.pm based on examples on the net) and still can't get it working.  
I'm using apache 2.2.17 and mod_perl 2.0.4.

so - I finally started digging into the Apache::DBI, DBD::mysql and 
DBD::Oracle packages -- I put in warn messages all over the place and 
turned on various debugs.  I see my debug messages from Oracle's ping 
call in the apache error log.  But I can never get the mysql ping to 
show its warn messages.  not via Apache::DBI's calls to it or my own 
forced ping call on the dbh.  So I can only conclude that it's not 
getting to the ping() method in DBD/mysql.pm

any idea where the mysql ping happens or why it's not?  is the top-level 
DBI package interfering?

(inserted right after the prepare method in the DBD::mysql::db package 
section)

sub ping {
      my ($dbh) = @_;
      my $ret = 0;
warn "DANDAN:  mysql ping!!";
      eval {
        local $SIG{__DIE__}  = sub { return (0); };
        local $SIG{__WARN__} = sub { return (0); };
        # adapt the select statement to your database:
        $ret = $dbh->do('select 1');
warn "DANDAN: selected 1";
      };
      return ($@) ? 0 : $ret;
}

similar warn messages in DBD::Oracle's ping show up just fine in Apache 
error log.

Dan