Scrolled TreeView and size allocation warnings

Hello, I recently posted a question on stackoverflow.com regarding GTK Warnings I recieve when running my application. You can read full question here on this link , but in

Size allocation warnings

Hi! I'm writing a Python app (gtimelog) that uses a Gtk.Paned to implement an optional side pane. I've an action ("win.show-task-pane") bound to a key (F9) that is implemented as a Gio.PropertyAction linked to the "visible" property of the Gtk.Box on the right. I also have a Gio.Settings