Bug#526030: I see this too.

[Daniel Burrows]

On Wed, Apr 29, 2009 at 05:41:06PM +0200, Josselin Mouette <joss at debian.org> was heard to say:
> Le mercredi 29 avril 2009 à 07:18 -0700, Daniel Burrows a écrit :
> > As of sometime between Sunday and today, this started happening to me
> > with the aptitude glade file (attached).  e.g., see the attached
> > screenshot of the packages_tab widget.
> 
> I think this is caused by the GTK+ upgrade. Now, GtkVBox implements the
> GtkOrientable interface. Internally, I guess it forces it to
> GTK_ORIENTATION_VERTICAL, but this must confuse glade which sets it to
> GTK_ORIENTATION_HORIZONTAL (the default).
> 
> Does it also happen with glade 3.6 in experimental? 

  It looks like it is fixed in 3.6.

  Daniel