gtk 1.2.9 and above introduced diagonal menu navigation a la Windows and
MacOS, but the timeout is much shorter than either system. Navigating the
menus works well if you're a fast mouse tracker, but less pointer-adept
users seem to be as frustrated as before. I suggest increasing the timeout
to infinity, as Qt and Windows seem to work well for said novices.
The working of the menu navigation system was significantly changed
for GTK+-2.2. We aren't going to do anything more here on 1.2 GTK+.