yumex must require pygtk2-libglade. It is not installed by the existing Requires for yumex.
Why, yumex is using gtkBuilder, not glade.
afaik gtkbuilder is included in gtk, so libglade is not needed
I have removed the 'import gtk.glade' upstream, It is not needed, and it will give errors if pygtk2-libglade is not installed :)