Finding cause of Gtk-CRITICAL in gtk_destroy_widget()

[Brenden Conte <conteb alum rpi edu>]

I have a line of code that looks like so:

gtk_widget_destroy(GTK_WIDGET(windowlist_entry->window));

where window is a (void *) in a struct, windowlist_entry.  Whenever this
line is run, i get the error:

Gtk-CRITICAL **: file gtkwidget.c: line 4880 (gtk_widget_unref):
assertion `GTK_IS_WIDGET (widget)'

However, if i switch gtk_widget_destroy with gtk_widget_hide, there are
no errors.  This tells me that there is something inside the window that
is causing this, but the error is useless in trying to find this
problem.

Does anyone have suggestions of how i might find what exactly is causing
this?
-- 
Brenden Conte <conteb alum rpi edu>