I can't get categories using my perl script

I try get categories(I have blog on wordpress.com) my perl script:

#!/usr/bin/perl

use strict;
use warnings;

use Carp;
use XMLRPC::Lite;

my $self = {
server => XMLRPC::Lite->proxy( "http://kun4.wordpress.com/xmlrpc.php" ),
blog_ID => '543282',
username => 'kun4',
password => '2023e9'
};
my $call = $self->{ server }->call(
'metaWeblog.getCategories',
$self->{ blog_ID } ,
$self->{ username },
$self->{ password }
);

#print $call->result;

$call->fault and croak 'get_categories: ', $call->faultstring;
my @categories;
push @categories, $_->{ categoryName } for @{ $call->result };
print map { "$_\n" } @categories;
##############

but everytime i get error:
Bad login/pass combination.
WHy ?

My script works good on standard wordpress installation(only one wp
blog, non MU)

Why ?

Please help me!!