title: Filestream create or append issue
body: <p>I am having issues with FileStreams. I'm in the process of writing a C# serial interface for FPGA project I'm working on which receives a packet (containing 16 bytes) creates and writes the bytes to a file and subsequently appends to the created file. </p>
  
  <p>The program is not throwing any errors but doesn't appear to get past creating the file and does not write any data to it. </p>
  
  <p>Any Ideas? IS there a better way to OpenOrAppend a file?</p>
  
  <p>Thanks in Advance, 
  Michael</p>
  
  <pre><code>    private void SendReceivedDataToFile(int sendBytes)
      {
          if (saveFileCreated == false)
          {
              FileStream writeFileStream = new FileStream(tbSaveDirectory.Text, FileMode.Create);
              writeFileStream.Write(oldData, 0, sendBytes);
              writeFileStream.Flush();
              writeFileStream.Close();
              saveFileCreated = true;
              readByteCount = readByteCount + sendBytes;
          }
          else
          {
              using (var writeFilestream2 = new FileStream(tbSaveDirectory.Text, FileMode.Append))
              {
                  writeFilestream2.Write(oldData, 0, sendBytes);
                  writeFilestream2.Flush();
                  writeFilestream2.Close();
                  readByteCount = readByteCount + sendBytes;
              }
          }
  
          if (readByteCount == readFileSize)                     // all data has been recieved so close file.
          {
              saveFileCreated = false;
          }
      }
  </code></pre>