Intuit Anywhere：无效的签名错误401

Question

我想要在特定日期之前获取帐户 我使用以下代码

TimeZoneInfo pst = TimeZoneInfo.FindSystemTimeZoneById("Pacific Standard Time");
        DateTime now = TimeZoneInfo.ConvertTime(new DateTime(2012, 06, 30), pst);
        accountQuery.CreateTime = now;
        accountQuery.SpecifyOperatorOption(FilterProperty.CreateTime, 
               FilterOperatorType.BEFORE);
        accountQuery.PageNumber = 1;
        accountQuery.ResultsPerPage = 100;
        string a = Response.ToString();
        List<Intuit.Ipp.Data.Qbo.Account> accounts =
           accountQuery.ExecuteQuery<Intuit.Ipp.Data.Qbo.Account>(context)
              .ToList<Intuit.Ipp.Data.Qbo.Account>();

但我收到错误未经授权的OAuth令牌：signature_invalid