A test failed in trying memcache

[liangasdf]

Codes:
---------
> cat aa.pl
#!/opt/csw/bin/perl

use Cache::Memcached;

my $cache = new Cache::Memcached {
    'servers' => [ "172.25.242.123:11211" ],
};


test( "1234" );
test( "12345" );
test( "aaaaa" );
test( "123456" );
test( "1234567" );
test( "12345678" );
test( "123456789" );
test( "1234567890" );

sub test()
{
    my $number = $_[0];

    print "====== Now set key[$number] --> value[aaa]\n";
    if( ! $cache->set( $number, "aaa" ) ) {
        print "Set Error \n";
    }

    print "Now try to get value of key[$number] ...";
    my $sss = $cache->get( $number );
    if( !defined( $sss ) ) {
        print "Cache get Error. Value [$sss]\n";
    } else {
        print "Cache get OK. Value [$sss]\n";
    }
}

But some of the keys are failed to operated.
> ./aa.pl
====== Now set key[1234] --> value[aaa]
Now try to get value of key[1234] ...Cache get OK. Value [aaa]
====== Now set key[12345] --> value[aaa]
Now try to get value of key[12345] ...Cache get Error. Value []
====== Now set key[aaaaa] --> value[aaa]
Now try to get value of key[aaaaa] ...Cache get Error. Value []
====== Now set key[123456] --> value[aaa]
Now try to get value of key[123456] ...Cache get Error. Value []
====== Now set key[1234567] --> value[aaa]
Now try to get value of key[1234567] ...Cache get OK. Value [aaa]
====== Now set key[12345678] --> value[aaa]
Now try to get value of key[12345678] ...Cache get OK. Value [aaa]
====== Now set key[123456789] --> value[aaa]
Now try to get value of key[123456789] ...Cache get Error. Value []
====== Now set key[1234567890] --> value[aaa]
Now try to get value of key[1234567890] ...Cache get Error. Value []

Need help! Thanks a lot!!!