I need to detect when a Bluetooth device is paired with N9. But I have not had any success with it. I'm sure I'm doing something wrong, but I have trouble finding the error.

First I thought I could use the QtMobility framework to detect these changes, like this:

    _btLocalDevice = new QBluetoothLocalDevice(this);

    connect(_btLocalDevice, SIGNAL(pairingFinished(const QBluetoothAddress &, QBluetoothLocalDevice::Pairing)),
            this,             SLOT(pairingFinished(const QBluetoothAddress &, QBluetoothLocalDevice::Pairing)));
Unfortunately the slot I've specified doesn't get called when a Bluetooth device is paired with N9.

So I looked at the D-Bus messages being sent when paring devices, and tried to connect using D-Bus like this:

    if (!QDBusConnection::systemBus().connect(QString(), QString(),
                                               "org.bluez.Device", "PropertyChanged",
                                               this, SLOT(propertyChanged(QString,QVariant))))
        qDebug("BluetoothClient::Failed to connect dbus signal isValid: %d", QDBusConnection::systemBus().lastError().isValid());
        qDebug("BluetoothClient::Failed to connect dbus signal type: %d", QDBusConnection::systemBus().lastError().type());
        qDebug("BluetoothClient::Failed to connect dbus signal: %s", qPrintable(QDBusConnection::systemBus().lastError().name()));
This code, I thought, should catch a signal whenever Bluetooth property is changed. One of the properties is "Paired" that I want to catch. But that slot is never called, and the connect returns an error. QDBusConnection::connect documents say service and path parameters are optional, and in the above example I've let them empty. But I have tried different values for them also but it's still failing.

Can anyone provide some hints or working code for this?

Thanks in advance.