mno dalo by se to vyresit pomoci signalu "button-press-event" a dale pak treba po kliknuti levym mysitkem pridat a pravym ubrat. viz zde: http://www.pygtk.org/docs/pygtk/class-gtkwidget.html#signal-gtkwidget--button-press-event pouzivam ho pro otevreni popup menu v treeview.