I did comment out line 752
/wp-content/plugins/s2member-pro/includes/classes/gateways/authnet/authnet-responses.inc.php
else if(in_array($s["card_type"], array("Visa", "MasterCard", "Discover", "Amex", "Maestro", "Solo")) && (!$s["card_verification"] || !is_string($s["card_verification"])))
$response = array("response" => _x('Missing Card Verification Code. It\'s on the back of your Card. 3-4 digits. Please try again.', "s2member-front", "s2member"), "error" => true);
also comment out line 614 this solves everything:
/wp-content/plugins/s2member-pro/includes/classes/gateways/authnet/authnet-checkout-in.inc.php
$authnet["x_card_code"] = $post_vars["card_verification"];
Thank you for quick reply :)