undef for @_ arglist when starting a poe session

I'm starting a poe session inside of a forked long running daemon.  I'm
wondering under what circumstances would the arglist passed to _start for a
new session be undef: I know the $poe_kernel is running and active because I
can dump it. If I try to dump $_[KERNEL] I get nothing.

use POE;
use POE::Component::Generic;
use Data::Dumper;



my $session = POE::Session->create(

        inline_states => {
            _start          => \&_start,

            create_message  => \&create_message,

            send_message    => \&send_message,

            _stop           => \&_stop,
        },
        options => {
            trace => 1,
            verbose => 1
        },
        args => [ $obj, $queue_manager ]

    );

sub _start {
      my ( $kernel, $session, $heap, $arg0, $arg1 ) = @_[ KERNEL, SESSION,
HEAP, ARG0, ARG1 ];

     print STDERR Dumper($kernel);
     print STDERR Dumper($poe_kernel);


}