Problem using on_dom_mouse_down in Gtk::MozEmbed

[Mark Hampton <mark hampton wanadoo fr>]

When I connect a callback to the on_dom_mouse_down signal I get the following
fatal error when the event is generated :

   Cannot set argument of type gpointer (fundamental type gpointer)

Would someone have some example code using this signal ?  Or a pointer as to
what might be going on.

Thanks,
Mark