When using TimeSpan objects doesn't expiry from couchbase

In version 1.3.6 here was a bug introduced when using Store method:
http://www.couchbase.com/communities/q-and-a/store-memcached-bucket-expi...

I upgraded to version 1.3.7 and it looks like this issue is still happening.

When I pass TimeStamp to Store method they don't expire at all.

our implementation:
public void Store(StoreMode mode, string key, object value, TimeSpan validFor)

{ tryExecuteStore(() => _client.ExecuteStore(mode, key, getObjectToStore(value), validFor)); }

private static void tryExecuteStore(Func<IOperationResult> executeStoreTask)

{ tryExecuteAndConvertExceptions(executeStoreTask, "Store"); }

private static void tryExecuteAndConvertExceptions(Func<IOperationResult> executeStoreTask, string logName)
{
IOperationResult result = null;
try

{ result = executeStoreTask(); }

catch (Exception exception)

{ logUnsuccessfulOperationAndThrow(logName, exception.Message, exception); }

if (!result.Success)
logUnsuccessfulOperationAndThrow(logName, result.Message, result.Exception, result.StatusCode);
}

private static void logUnsuccessfulOperationAndThrow(
string operationType, string message, Exception exception, int? statusCode = null)
{
message = String.Format("Error during

{0} operation: {1}", operationType, message);
if (statusCode.HasValue)
message = String.Format("{0}

(

{1}

-

{2}

)", message, statusCode.Value,
((CouchbaseStatusCode) statusCode.Value).ToString());

_logger.Error(message, exception);
throw new CouchbaseException(message, exception,
statusCode == null ? default(CouchbaseStatusCode?) : (CouchbaseStatusCode) statusCode);
}