Comment 2 for bug 585727

Yes, that's exactly the case.
I open up terminator (version 0.93), I create a new tab, then I "roll" back to the first tab (using my mouse wheel) and there I get the message at the prompt:

/usr/bin/terminator:74: GtkWarning: gtk_widget_is_ancestor: assertion `ancestor != NULL' failed
  gtk.main()

However, I have just noticed that if I "click" back to the first tab (left mouse click) strangely enough I don't get the error!!?!! Weird??
I guess it's not very important though (if it's not linked in a way to the problem with saving the layout)

For information:
I am running ubuntu 10.04 (x32) and
gtk+2.0: Package: libgtk2.0-dev, Version: 2.20.1-0ubuntu1
pygtk: Package: python-gtk2-dev, Version: 2.17.0-0ubuntu2

Thanks!