Does this input method work in the non-web portions of the browser (search entry and locationbar)? If not, this is a GTK+ bug rather than a Midori one; it may be the case the GTK+ doesn't understand alt+numpad input.
Does this input method work in the non-web portions of the browser (search entry and locationbar)? If not, this is a GTK+ bug rather than a Midori one; it may be the case the GTK+ doesn't understand alt+numpad input.