Re: doc of prompt change with minor mode for read-key-sequence?

[Richard Stallman]

    It is the map for a global minor mode, Icicles. It functions as a menu-bar
    menu map, and there are also keyboard sequences bound in it.

To make the menu-bar menu work, you need to give a prompt string aka
menu name to the map that you put on the prefix key menu-bar.  But you don't
need to give a prompt string aka menu name to the overall keymap for
Icicles.  That never needs to operate as a menu.

So try removing the arg to make-sparse-keymap when you make the
overall keymap, and see if everything works right.