[Vala] Gstreamer : cannot connect signal to GstTypeFindElement

[Frédéric Gaudy <fred_gaudy yahoo fr>]

Hi,

I'm using the Gst.Element "typefind" to detect the stream capabilities.
But when connecting to its specific signal "have-type" I've got this runtime message :
GLib-GObject-WARNING **: IA__g_object_connect: invalid signal spec "have-type"

My code is :
Gst.Element typefinder = Gst.ElementFactory.make("typefind", "typefinder");
typefinder.connect("have-type", this.on_have_type, this);

It return a GstTypeFindElement which isn't declared in gstreamer.vapi because it's loaded as plugin.

If I query signals from this type I find :
    id : 325
    signal_name : have-type

Some ideas?