winform webhttprequest报500错误

前几天给一个客户换了server随后就出现了如下报错问题远程服务器返回错误: (500) 内部服务器错误。这是部分代码
try
            {
                /*** REQUEST TO HQ ***/                // Create a request using a URL that can receive a post.
                WebRequest request = WebRequest.Create("地址");
                // Set the Method property of the request to POST.
                request.Method = "POST";                // Create POST data and convert it to a byte array.
                string postData = "table=InventoryUpdate&xml=" + ss + "&storeId=5";
                byte[] byteArray = Encoding.UTF8.GetBytes(postData);                // Set the ContentType property of the WebRequest.
                request.ContentType = "application/x-www-form-urlencoded";                // Set the ContentLength property of the WebRequest.
                request.ContentLength = byteArray.Length;                // Get the request stream.
                Stream dataStream = request.GetRequestStream();                // Write the data to the request stream.
                dataStream.Write(byteArray, 0, byteArray.Length);                // Close the Stream object.
                dataStream.Close();                /*** RESPONSE FROM HQ ***/                // Get the response.
                WebResponse response = request.GetResponse();                // Display the status.                Console.WriteLine(((HttpWebResponse)response).StatusDescription);                // Get the stream containing content returned by the server.
                dataStream = response.GetResponseStream();                // Open the stream using a StreamReader for easy access.
                StreamReader reader = new StreamReader(dataStream);                // Read the content.
                responseFromServer = reader.ReadToEnd();                // Clean up the streams.
                reader.Close();
                dataStream.Close();
                response.Close();
            }            catch (WebException ex)
            {
                ex.ToString();
            }
            return responseFromServer;
将客户地址转到我们的测试服务器上又可以用了，估计是服务器配置问题。求大牛们指正