sasl bind with GSSAPI

[TOMOE H. <rm@IT.Fh-Worms.DE>]

hi,

I've got problems binding with sasl and gssapi.
I'm using:

ii  libnet-ldap-perl  0.26-2            A Client interface to LDAP servers.
ii  libauthen-sasl-pe 2.03-1            SASL Authentication framework
ii  libauthen-sasl-cy 0.06-1            Perl extension for Cyrus SASL library
ii  libsasl-dev       1.5.27-3.3        Development files for authentication abstraction l
ii  libsasl-gssapi-mi 1.5.24-15         Pluggable Authentication Modules for SASL - MIT GS

As far as I could get was this:

=========
$
./ldap-test1
GSSAPI: gss_accept_sec_context: A token was invalid; Token header is malformed or corrupt;  
at ./ldap-test1 line 19
=========

ldapsearch or even my small self written ldap-sasl-search work fine though.
Here is ldap-test1:

=========
#!/usr/bin/perl -w

use strict;
use Net::LDAP;
use Authen::SASL;

my $ldap = Net::LDAP->new('hopser.hotaru.it.fh-worms.de', version => 3, onerror => "die");
$ldap->start_tls(verify => 'none');

my $root = $ldap->root_dse(attrs => ['supportedSASLMechanisms']);
my $sasl = Authen::SASL->new(
#       mechanism => join(' ',$root->get_value('supportedSASLMechanisms')),
        mechanism => 'GSSAPI',
        callback => {
                'user' => '',
                'password' => '',
        },
);
$ldap->bind(sasl => $sasl);
=========

Any help welcome...
thanks