title: QtSerialPort example fails
body: <p>I am using Qt 5.1 and when my app (which worked using QextSerialPort in v4.8.4) failed to communicate, I tried the example in ...\5.1.1\Src\qtserialport\examples\serialport\terminal.   And that fails too.</p>
  
  <p>I have a simple USB dongle that emulates a COM port.   If I use RealTerm, I can send AT commands to it and get back OK just fine.</p>
  
  <p>But the terminal example that comes with Qt does not communicate with it.   I looked at an API snooper, and I am getting an unsuccessful return with error of "997:Overlapped I/O operation is in progress" for WaitCommEvent and WriteFile.</p>
  
  <p>I am running it on Windows 7, and I copied the exe and DLLs over to a Windows 8 machine, and it failed to communicate as well (though I didn't do the API snooping there).</p>
  
  <p>Anyone have any ideas what to try?   How can the unmodified example app just plain fail?  I am befuddled.</p>