Cannot get realize() events on GtkViewport created by libglade

[david hagood gmail com]

I'm trying to build an app that will use Glade+libglade to build its user
interface. I'm going to have some custom widgets in the app, and since I
have yet to get enough information to know how to create a catalog for
Glade or Gazpacho containing my custom widgets, I cannot simply let
libglade create them, as would be my preference.

So, my thought was to hook into some "constructor-like" event for some
container widget, and then create my custom widgets in that event
callback. That way I could at least begin to make progress.

It *looked* like the realize/unrealize events were what I needed, however,
when I hook them they don't get called. If I change the .glade file to
hook, say, a button press, my event callbacks happen, so I know that at
that level my code is working.

I am hooking the events as "after" events, so that they should be called
in addition to any other events.

OK, so - what am I doing wrong here?