change:
$WAFV_Errors .= WAValidateLE($_SESSION['captcha_Security_Code_1'] . "",((isset($_POST["Security_Code_1"]))?$_POST["Security_Code_1"]:"") . "",true,7);
to:
$WAFV_Errors .= WAValidateLE(strtolower($_SESSION['captcha_Security_Code_1']) . "",((isset($_POST["Security_Code_1"]))?strtolower($_POST["Security_Code_1"]):"") . "",true,7);