Cant connect to memcached server error 47

Hi all,

I have memcached running locally and on another server (via vpn), I can successfully communicate with either server from phalcon using the code below:

        $memcache = new Memcached;
        $memcache->addServer('memcache.server.com',11211);  
        echo $memcache->save('trackinglink-50164','https://www.google.com',60;
        echo $memcache->get('trackinglink-50164');

However using Phalcon libmemcached I get:

Uncaught Phalcon\Cache\Exception: Failed storing data in memcached, error code: 47

Here is my service:

$di->set('cache', function () {     
    $frontCache = new FrontData(
        array(
            'lifetime' => 86400,
        )
    );

    $cache = new \Phalcon\Cache\Backend\Libmemcached($frontCache, array(
          "servers" => array(
              array('host' => 'memcache.server.com',
                    'port' => 11211,
                    'weight' => 1),
          ),
          "client" => array(
              Memcached::OPT_HASH => Memcached::HASH_MD5,
              Memcached::OPT_PREFIX_KEY => '',
          )
      ));   

    return $cache;  

})

Here is a print_r of $cache:

     Phalcon\Cache\Backend\Libmemcached Object
(
    [_frontend:protected] => Phalcon\Cache\Frontend\Data Object
        (
            [_frontendOptions:protected] => Array
                (
                    [lifetime] => 86400
                )

        )

    [_options:protected] => Array
        (
            [servers] => Array
                (
                    [0] => Array
                        (
                            [host] => memcache.server.com
                            [port] => 11211
                            [weight] => 1
                        )

                )

            [client] => Array
                (
                    [2] => 1
                    [-1002] => 
                )

            [statsKey] => 
        )

    [_prefix:protected] => 
    [_lastKey:protected] => 
    [_lastLifetime:protected] => 
    [_fresh:protected] => 
    [_started:protected] => 
    [_memcache:protected] => 
)

trying the code below triggers the error:

$cache = Di::getDefault()->getCache();
$cache->save('mydata',array(1,2,3));

I can also telnet to either server, set and get keys just fine.... funny is, code above was working before and all of a sudden I keep getting this error 47 and can no longer do anything....

Can anyone help?