If I am trying to connect to an invalid host, and, after the connection fails, I try to connect to a valid host, the connection still fails.
Qt Code: 
  1. void testSoc::test()
  2. {
  3.    switch (state)
  4.    {
  5.       case 0:
  6.       case 2:
  7.       case 4:
  8.          qDebug ("Connecting to a valid host. Should be Ok");
  9.          timeout->start(10000);
  10.          soc->connectToHost(VALID_HOST, VALID_PORT);
  11.          break;
  12.       case 1:
  13.          qDebug ("Connecting to a invalid port. Should fail");
  14.          timeout->start(10000);
  15.          soc->connectToHost(VALID_HOST, INVALID_PORT);
  16.          break;
  17.       case 3:
  18.          qDebug ("Connecting to a invalid host. Should fail");
  19.          timeout->start(10000);
  20.          soc->connectToHost(INVALID_HOST, VALID_PORT);
  21.          break;
  22.    }
  23. }
  24. void testSoc::checkConnection()
  25. {
  26.    timeout->stop();
  27.    if (soc->state() == QAbstractSocket::ConnectedState)
  28.    {
  29.       connected();
  30.    } else {
  31.       qDebug ("Connection failed");
  32.       soc->disconnectFromHost();
  33.       if (soc->state() != QAbstractSocket::UnconnectedState)
  34.          soc->waitForDisconnected();
  35.       soc->close();
  36.       //delete soc;
  37.       //soc = new QSslSocket;
  38.       state ++;
  39.       test();
  40.    }
  41. }
  42.  
  43. * and of course there is 
  44.  
  45.  connect (soc, SIGNAL(connected()),
  46.         this, SLOT(connected()));
  47.    connect (timeout, SIGNAL(timeout()),
  48.         this, SLOT(checkConnection()));
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In this code, all gives the expected results, except for case 4 (including case 2, reconnecting after trying to connect to a valid host, with invalid port)

deleting and re-creating the socket does not help
(using Qt 4.4.3)