I'm observing a weird problem while trying to emit a signal defined by a
GstElement from a Python script. The signal is defined as follows:

  dvdblocksrc_signals[QUEUE_EVENT_SIGNAL] =
    g_signal_new ("queue-event",
        G_TYPE_FROM_CLASS (klass),
        G_SIGNAL_ACTION,
        G_STRUCT_OFFSET (DVDBlockSrcClass, queue_event),
        NULL, NULL,
        gst_marshal_VOID__POINTER,
        G_TYPE_NONE,
        1, GST_TYPE_EVENT);

i.e. it receives a GstEvent and returns void. I try to emit it using a
line like

        element.emit('queue-event', someEvent);

The result is an exception with the following error message:

  TypeError: could not convert type gst.Event to GstEvent required for parameter 0

I tried modifying the signal definition to receive a GstData value, but it
failed with a similar error message.