Comment 4 for bug 1299838

You can fix it manually by editing the file gtk-widgets-assets.css on /usr/share/themes/Radiance/gtk-3.0/

Find the line (#421): .menu .radio:active {
which is followed by a line including url("assets/radio-menuitem.png")

It should be ".menu .radio:active:hover" (without quotes). That's it.