Dialog hide/destroy

["Juan José 'Peco' San Martín" <peco microbotica es>]

Hello all.

In order to understand how the window widgets works, I created a minor
application.
One windows with two buttons in order to hide or show another window.
All is correct! :-)

Now, I'm trying to do the same but using a main window with Menu widget
that calls a new "dialog" window. All seems to be ok, but if I close
dialog window (delete_event) and try to re-open again (clicking on the
menu of the main one) I get:

Gtk-CRITICAL **: gtk_container_foreach: assertion `GTK_IS_CONTAINER
(container)' failed at ...

when I try to show the dialog again.

BTW, what it's the different between of using "hide"/"show" or directly
"destroy" to control de windows behaviour?. It is always recommended one
way to do it?. Is it faster vs memory-lesser?

Thanks!
Peco